Abstract: Due to its global coverage,LEO(Low-Earth-Orbit) satellite network is becoming more and more important for providing Internet and other services.However,a main technical challenge about LEO satellite is how to design a reasonable and efficient mechanism to optimize its Service Area Allocation.The difference between Footprint and Service Area were analyzed.It pointed out that the traditional allocation mechanism would lead to the mismatch between service requirements and LEO satellite network capacity.To improve the situation,an on-board real-time Service Area Optimization Algorithm(SAOA) was proposed and the simulation results prove that,SAOA can alleviate the mismatch between service requirements and network capacity,reduce the blocking probability and improve the network performance significantly.