Green and energy-saving heterogeneous cellular networks are the trend of future mobile communication networks, and there are also a series of problems such as resource allocation, load balancing, and energy-saving design. As an important component of energy consumption in cellular networks, base stations have the characteristics of regularity and periodicity of services, so the introduction of base station dormancy technology can effectively save energy while ensuring the quality of service for users. Aiming at the sleep problem of base stations in heterogeneous cellular networks in urban areas, this paper analyzes the sleep probability and power consumption model of distance-aware micro base stations in sleep mode. Aiming at minimizing system power consumption, a sleep scheme in which macro base station and micro base station cooperate horizontally is designed. For the multi-constraint problem of user transfer in horizontal cooperation, a heuristic algorithm is proposed. The results show that the proposed cooperative scheme can save a lot of energy when the user SINR loss is small .