The weight reduction design method of a micro turbojet engine compressor is studied numerically in this paper. Firstly, the finite element calculation is carried out on the solid compressor, and the stress and deformation data of the compressor structure under the condition of the design speed are grasped, which is used as the design constraint space for the weight reduction optimization. On this basis, the weight loss optimization design of the solid part of centrifugal compressor disc is carried out with the help of the characteristics of high strength and high stiffness of honeycomb structure. The results show that the weight loss of the compressor can reach 22% under the condition that the equivalent stress of Mises is not increased and the radial displacement of the tip of the blade is not significantly increased compared with the load bearing capacity of the compressor before and after optimization.