Economic crisis is a term reserved for capitalist conditions. It refers to overproduction caused by a severe lack of effective demand. As long as there is enough effective demand, then even inflation will not cause a crisis. Fundamentally, it still has to be explained in terms of the movement of the basic contradictions of capitalism. The movement of capitalism's basic contradictions has stages, and the sharpening of the basic contradictions is one of the stages, one of the manifestations of this movement process. When the basic contradictions tend to sharpen, under the interaction of other important contradictions in the economic field (e.g. the contradiction between production and consumption, the contradiction between the enterprise production and the social production, etc.), the economic crisis will break out. Specifically, there are the following reasons. Firstly, it is caused by the imbalance of economic structure, that is, the so-called structural crisis. Among them, the imbalance of industrial structure is the centralized manifestation. The industrial structure directly triggers the contradiction in the employment structure and product structure, which leads to economic chaos and crisis. The large-scale adjustment of economic structure, if not handled properly, may also cause overproduction of economic crisis. Secondly, the contradiction between production and consumption triggers. Especially important means of production for a long time backlog of serious surplus, once spread to other areas, may trigger a crisis. Thirdly, it is caused by the failure of the government's macro-control policy measures. The government used to macro-control monetary policy, fiscal policy, industrial policy, income policy, such as the use of inappropriate, will also induce economic crisis. Fourth, when the world economic downturn or a country in a field of serious problems, may trigger a regional economic crisis or even a global economic crisis.