The invention relates to an access method and system when M2M equipment is accessed to a base station. The method comprises the steps of: calculating the lead code conflict probability when M2M equipment positioned in an overlapped cellular area selects an access base station; and, performing base station selection and power distribution of the M2M equipment in the overlapped area by using a non-cooperative game having the optimal energy efficiency, so that the M2M equipment having the optimal energy efficiency is accessed to the base station. By means of the technical scheme provided by the invention, the access success rate when the large-scale M2M equipment is accessed to a network in an overlapped cellular network can be increased; furthermore, energy required by equipment communication can be effectively reduced; and the communication energy consumption can be increased.