To obtain the cumulation profile of pulsar signal, the traditional method needs to identify its period first, and then fold the signal with the period. This method depends on the accuracy of the period, and it has no evaluation standard for the profile. In this paper we analyze the strong correlation between the cumulation profile and the period, and present a minimum entropy method of pulsar cumulation profile and its verification. Therefore this method is applied to the identification of pulsar cycle. The RXTE data and the simulation data are used to verify the effectiveness of the method.