Aiming at the current situation that the planning of unmanned aerial vehicle (UAV) spraying has not reached the maximum energy utilization rate, target for the shortest total path, payload and safe operation, a combined algorithm of UAV spraying planning based on energy optimization was researched. Using grid method to divide working area, after getting full coverage, the return points can be distributed rationally and the payloads of sorties by setting up supply points, which reduced energy consumption rate of UAV from route and path and improved operational efficiency. The simulation results of the algorithm by the designed mating software of earth station showed that under the same operating conditions, compared with traditional spraying planning which based on drug or energy exhaustion but had occasional forced landing or crash risk, using the combination algorithms to plan the spraying of UAV can save rate of range planning about 16.25% and that of load planning about 18.92%. From the field contrast test, the algorithmplanned operation saved 2725m returning flying range compared with the nonalgorithmplanned operation. The savings rate of flying range was 23.7%. And it can save load about 1L, which meant that the saving rate of load was 16.7%. In summary, this combinational algorithm can save energy effectively and ensure that only when their energy satisfied the safeguard requirement, UAV would operate, and it furtherly verified the energy saving and security of the algorithm.