Abstract: Aiming at the problem that high transmission energy consumption caused by offloading computation tasks from ground nodes set to low earth orbit satellite edge server in the satellite-ground computation offloading scenario. In order to improve the battery life of the nodes set and effectively utilize the computation resources in the network at the same time, a partial computation offloading scheme of bilateral cooperation is proposed combined with device-to-device communication. Considering that the processing delay of computation tasks and the load of low earth orbit satellite edge server are limited, the optimization problem is modeled as minimizing the total energy consumption of the ground nodes set during the offloading process, and the improved genetic algorithm is used to solve the problem. The algorithm arranged the individuals in the population by descending order according to the size of fitness value and crossed them in pairs, and give the individuals with smaller fitness higher mutation probability. The simulation results show that the improved genetic algorithm converges well under different delay requirement and task node numbers, and effectively reducing the energy consumption of ground nodes set during the offloading process.