Abstract: Genetic tests on the remains of Emperor Wu of the Northern Zhou Dynasty revealed that he died of chronic arsenic poisoning.The cause of death was determined for the first time,and his portrait was restored according to molecular biology,providing conclusive new evidence for the study of medieval China; this is an essential basis and starting point for reunderstanding the political process of this period.According to the records of Buddhism and Taoism,the relationship between Emperor Wu,Taoist priests and the elixir of food was examined,and it was found that there was a group of Taoist priests around him,which were divided into alchemists and theoretical Taoist priests,they all strongly rejected Buddhism.However,Emperor Wu's prohibition of Buddhism was not instigated by Taoist priests as general theory suggests,but by a political decision with deep deliberation: to promote the integration of Hu and Han and enhance national governance with social cohesion.The Sui and Tang Dynasties inherited this policy,and it became the primary direction for reshaping the country's mainstream culture.