Abstract: Based on rigid-flex coupled multi-body system dynamics and Virtual Prototype Technology (VPT). A co-simulation platform was constructed with the softwares of Pro /Engineer, ADAMS, Matlab and ANSYS, and then a rigid-flex coupled virtual prototyping model of shearer with flex cutting unit planet carrier and haulage unit second planet carrier was built. Through dynamics simulation analysis results found out that the planet carriers’ weak link were in the integral key seat, and the cutting unit planet carrier mainly bearing bending moment while the haulage unit second planet carrier mainly bearing torsion moment. Haulage unit second planet carrier was optimized based on satisfied transmission ratio, concentric condition, equispaced condition, and adjacency condition. The optimized planet carrier’s strength and stiffness were improved through increasing solid material of weak link, reducing axial dimensions, increasing radial dimension, and changing bearings’ configuration form. At the same time, the shear’s service life was effectively extended.