In the old Shanghai before liberation, forces from all sides gathered here, mixed with good and bad, and turbulent. This is a playground for the powerful, a purgatory for the poor and a well-deserved magic capital. Sanmao (Meng Zhichao) is a little boy with a round head and only three hairs. He lost his father when he was a child. In order to find his mother who went out to make a living, the inexperienced boy came to Shanghai. In this city where big capitalists, warlords, speculators, foreigners, hooligans, swindlers, thieves, dancers, prostitutes and millions of poor people in Qian Qian are gathered, Sanmao has tasted the ups and downs and seen the strangeness of this chaotic era. His weak arms carry too many things that are inconsistent with the age of this flower season, but even so, Sanmao still maintains a kind and upright character. ...

In order to survive, he sold newspapers, picked up cigarette butts and helped others push rickshaws, but he was always bullied. Only street children with the same fate care about him and give him warmth. Later, he was tricked into stealing by a rogue uncle. The kind Sanmao refused and escaped. Soon, he was adopted by a rich and barren woman. San Mao doesn't like the hypocritical and decadent life of rich people. When a lady held a cocktail party for him, she mixed with a group of street children and disrupted the reception. Then, Sanmao took off her gorgeous clothes, put on a sack and returned to the ranks of street children.

Shanghai was liberated, and Sanmao happily welcomed the arrival of a new life. Zhang Leping is an accomplished artist. He created a lot of cartoons in his life and achieved great success. His masterpiece The Wandering of San Mao mercilessly lashed out at the cruelty, cruelty, fraud and injustice of the old society. It eulogizes the "San Mao Spirit" which is still strong, optimistic, kind, alert and humorous in extreme hardships. Sanmao's story aroused the cries of all good people. Zhang Leping and his San Mao live in the hearts of China people from generation to generation. Zhang Leping is known as "the father of Sanmao" and "Grandpa Sanmao".