In view of the complex characteristics of the internal process scheduling problem of the maintenance support system, such as multiple processes, different types of maintenance personnel, and different levels of maintenance personnel, this paper establishes a multi-objective and multi-constraint optimization model with the shortest maintenance man-hour and the minimum total human resource load as the objective function. The priority value encoding based on the critical path algorithm is used to code the preemptive scheduling problem at the first level, and the second level human resource code is obtained by using a random generation scheme, and then a crossover algorithm that meets the preemptive scheduling is designed for the hybrid particle swarm genetic algorithm. We use Matlab software to simulate the examples of non-preemption, one-time preemption, and multiple preemption scheduling schemes respectively, and finally compare and analyze the simulation results, through which we obtain a multi-process preemptive maintenance process scheduling scheme under the constraints of multi-work and multi-level human resources, as well as the objective function solution corresponding to the scheduling of no preemption, one preemption, and multiple preemption. Decision makers can set the weight of the objective function according to actual needs to get the best scheduling plan.