In the first half of the 20th century, Chinese society was at a crossroads of historical development, with a complex political situation and a surging labor movement. In Changxindian, an ancient town in southwest Beijing, Kang Benshan, a young and poor locomotive factory worker, dreamed of "being a great craftsman, repairing the most difficult machines, and building the best trains". Under the guidance of the party organization, he united the workers' forces with Wang Ranqiu, Wang Sen, Wu Shiju and other progressives to establish workers' clubs, escort strike donations, protect technical backbones, resist Japanese aggression, arrest Kuomintang spies, etc., and gradually grew and matured in the process of fighting against various reactionary forces. After the founding of the People's Republic of China, he and Wang Ranqiu, as engineers and couples of the Erqi Locomotive Factory, made important contributions to the development of new locomotives and became real "great craftsmen".