Wang was born in Bijie, Guizhou Province, and became a table tennis player in 1958. A year later, he was chosen into the Chinese national team. At the 1963 World Table Tennis Championships in Prague, 19-year-old Wang Jiasheng was a member of the Chinese team (along with Zhuang Zedong, Li Furong, Xu Yinsheng, and Zhang Xielin) that defeated Japan to win the men's team championship, for the second time in Chinese history. Wang also won the bronze medal three times in men's doubles of the 1961, 1963, and 1965 world championships, with partners Zhou Lansun and Li Furong.