Cheng Yu is a significant yet underexplored figure in modern Chinese history. His ideas on Confucianism were closely linked to three pivotal moments of crisis in modern Chinese history: The First Sino-Japanese War, the May Fourth Movement, and the Second Sino-Japanese War. The First Sino-Japanese War led to the Qing government’s Hundred Days Reform, initiated by Kang Youwei in 1898. When the Reform failed, Cheng, the secretary of Timothy Richard, assisted Kang in his escape and became Kang’s disciple. In 1906, he traveled to Japan to investigate the development of industries, manufacturing, and hospitals, but his primary interest lay in Japan’s educational model. Cheng believed that China’s education lacked moral advancement compared to Japan’s, and he deemed it necessary to promote practical learning and moral education. Following the May Fourth Movement in 1919, he vigorously advocated moral instruction and hoped the government would establish Confucianism as the state religion. He believed it was the only way the government could preserve the country’s culture and save China from imminent destruction. Cheng’s ideas of Confucianism were emblematic of his era. In 1938, he attempted to reform Confucianism and promote Confucian moral education in the school system by cultivating the Chinese people’s cultural confidence and national identity. Cheng’s solution to China’s moral crisis was a response to the challenging question of the modern fate of Confucian China.