Is Ai Weiwei the most famous artist in the world? If so, it’s not because of his art but because of his celebrity status as a political dissident who’s been carefully shoehorned by the media — and sections of the cultural establishment, judging from some of the accompanying notes to this exhibition — into the liberal stereotype of the heroic individual artist defying communist tyranny.

To some extent, the question of whether this is a fair interpretation of his art gets a response in this large and varied exhibition, some of it site-specific, which provides an opportunity to assess the aesthetic and political qualities of Ai’s art.

Curiously, the least successful pieces are the most directly political ones focusing on Ai’s own disputes with the authorities. There are handcuffs, camcorders and CCTV cameras crafted from marble and a porcelain map of China’s regions with the slogan “free speech” on each of them. They show skilful craftsmanship but their deliberate uselessness as objects and superficial political content make them seem bombastic and crude.

Six iron boxes with dioramas of half-size, lifelike figurines tell the story of his imprisonment on suspicion of tax evasion a few years ago. While it must have been very stressful to live for several weeks under the gaze of guards, the literal, “cute” way the scenes are depicted drains them of any disturbing effect.

The echoes of the kitsch and jejune styles of official art under Mao undermine their power as political protest.

Some other pieces show similar strands of self-glorification and half-hearted, unconvincing conformity to certain well-worn Western artistic and political tropes.

In one triptych of photographs, Ai vandalises a Han dynasty vase by smashing it on the ground. Other ancient vases are dipped in bright industrial paint and daubed with the Coca-Cola logo and echoes of Duchamp. Crudely iconoclastic Dadaism and the more nihilist elements of Warhol-inspired art are painfully obvious in these derivative pieces.

Yet there are other much more authentic and heartfelt artworks. One room is dedicated to the 2007 earthquake in Sichuan which killed 5,000 schoolchildren, partly due to the shoddy building materials and techniques used by corrupt local authorities. The victims are memorialised, not only in videos, photographs and lists of their names on the gallery walls, but most strikingly through Straight, a 50-foot-long installation laid across the floor of the gallery.

It’s a massive, beautiful construction using the reinforcing bars from the badly built school buildings. They were crumpled and twisted by the earthquake but have been straightened and then laid in gently undulating but unsettled waves, reminiscent of the seismic movements which caused the tragedy. It is a sombre, grieving and dignified monument to the victims and a particularly sensitive kind of artistic and political activism. As Ai says: “Everything is art. Everything is politics.”

Another of his aphorisms, “I want people to see their own power” is expressed in much of his previous work. He helped design the famous Bird’s Nest stadium in Beijing, whose interlocking beams evoke fairness, mutual interdependence and social equality.

His installation of millions of sunflower seeds, supposedly China’s historic symbol of life and hope in adversity, in the Tate Modern’s Turbine Hall a few years ago was similarly memorable — a brilliantly original affirmation of hope and belief in the communist vision of similar yet separate individuals, living and growing together in a class-free society. The same feelings of respect for history, delight in craftsmanship and worked materials and an underlying faith in communal harmony are expressed in several brilliantly conceived and executed pieces in this exhibition.

The most abstract and imaginative expression is Fragments, a structure of intersecting beams taken from temples, sometimes driven through antique chairs and tables. The beams are fixed together without nails or screws, using traditional Chinese joinery methods and represent a kind of 3-D map of China, both formally geographical but also psychosocial. It invites the spectator to walk around and through it and it exudes history, strength and anxiety, along with a certain disquiet and subversive discontent, together with an exuberance at the power of the social, the joined and the co-operative.

Other pieces, more straightforwardly representative, conform with another of Ai’s sayings, that “ordinary people should have the same ability to understand art as anyone else.” In one room, a sparkling and uplifting chandelier made of bicycles rotates very gently in the air, a wonderful homage to all the ordinary working people who have contributed their labour to building the modern Chinese republic. In another, vibrant tufts of grass are given a monumental quality by being carved out of marble. Like the sunflower seeds, they are all similar yet subtly different — a confident and empowering vision of Chinese people and society.

Kippe is a stack of old and beautifully mellowed pieces of wood, salvaged from ancient temples. Fashioned into a tightly fitting, smooth-faced and harmonious block, strengthened and supported by gymnasts’ parallel bars, they reference the leading role of the Communist Party in maintaining and developing social harmony amongst the common people of China.

“My art becomes more and more political,” says Ai and it’s clear that his activist art is designed not just to interpret the world but to change it. It’s also clear from this exhibition that his political critique is not limited to repressive features of the Chinese state but is implicitly opposed to societies divided by class wherever they are. Ai’s best work summons up and celebrates the age-old communist vision of individuals living in egalitarian social harmony. By doing so in such an invigorating, empowering and pleasing way, it surely helps us achieve a society where we will indeed be “people who see their own power.”