By reviewing the 40year history of Chinas reform, this paper finds that the reform shows an obvious cyclical change law, and there is a medium cycle and three short cycles. The fundamental reason for the reform of the cyclical change law is that as the adjustment of the production relationship, the reform must follow the law of change in the production relations to adapt to the changes in the development of productive forces. In addition, Chinas reform adopts a gradual reform approach, which makes the changes of production relationship have phased features, and it causes the phased change of productivity development, which forms a high degree of consistency between the reform cycle and the economic cycle. The cyclical change law of reform is of great significance for comprehensively deepening reform in the new era: the downward pressure on the economy is precisely the best window for reform; the reform enters the new cycle, which can breed a new cycle of economic operation; and stimulate the peoples reform passion and vitality. In order to promote the reform of the cyclical movement; strengthen the toplevel design, in order to promote the comprehensive deepening of reform.