The stock market is a typical representative under the market economic system，as well as a kind of complex mixture of the politics，economy，culture and institution. Crash can also be regarded as an ideal model of the experimental research of sick society. The study found that the government is not only a regulator，but also a participant. The stock market has both economic attribute and “Group commitment” attribute at the same time. Economic attribute means that the stock market is related with the national macro economy and industrial reform. The “Group commitment” attribute means that under the centralized system and stock market audit system，the national credit is responsible for the stabilization of the stock market. Under the circumstances，when a stock crash occurs，through a series of game and negotiations，the market would exit spontaneously and show its “loyalty”，to integrate and mobilize to make the government involved in. The market gradually formed a “focal point”，and a system of political discourse. Politicization is the characteristics of governmental intervention to the market under centralized system，as well as the results of an unclear rights structure.