Abstract: Electric vertical take-off and landing aircraft(eVTOL) puts forward strict requirements for light weight, stable operation and high efficiency of the drive motor. Although the traditional radial flux motor has the advantages of mature manufacturing process, reliable mechanical structure and low cost, it has the problems of large weight and volume, low efficiency, torque density and power density. In view of the above problems, a design and multi-objective optimization method of PCB axial flux Halbach permanent magnet synchronous motor(PCB-AH-PMSM) with double rotor structure is proposed, so as to realize the lightweight structure and smooth operation of the motor, and improve the torque and operation efficiency of the motor. Firstly, the finite element analysis(FEA) model of the motor is established, and its electromagnetic characteristics are systematically analyzed to verify the rationality of the initial design. Then, the Latin hypercube sampling(LHS) method is used to sample the optimization variables and the global sensitivity analysis is carried out to screen out the key influencing parameters. Finally, a high-precision response surface is constructed based on the Kriging model. The output torque, torque ripple, eddy current loss and electromagnetic efficiency are taken as the optimization objectives. Particle swarm optimization(PSO) is used to carry out multi-objective optimization, and the results of the surrogate model are compared with those of FEA. After optimization, the output torque of the motor is increased by 34.87%, the torque ripple is reduced by 45.45%, the eddy current loss is reduced by 8.1%, and the electromagnetic efficiency is increased by 2.01%, which proves the effectiveness, accuracy and feasibility of the optimization method. It provides an efficient and reliable motor solution for eVTOL and other aerospace drive systems that are sensitive to weight, running stability and efficiency.