According to the eccentric structure and high-speed characteristics of scroll compressor rotor,a parametric finite element modeling program for spindle components was developed by equivalent configuration of the elements like finite strain beam,2D bearing and 3D space mass etc.The Campbell diagram and critical speed of the spindle were obtained by running the rotor dynamics analysis under the influence of gyro effect.On the basis of the variables that consisted of the counterweight mass (m1,m2) and its centroid position ( R1,R2),the dynamic optimization of the rotor assembly was conducted,not only its first-order critical speed was increased by 4.2%,but also the total weight of the counterweight and the maximum stress amplitude were reduced by 0.413 kg and 0.21 MPa,respectively,reaching the expectation of the lightweight design.The simulation flow of fatigue analysis project in S-N stress form was constructed by using nCode DesignLife software,and the crankshaft fatigue analysis and damage assessment were realized under time series load mapping with multiple working conditions.The results show that the lightweight design can improve the minimum fatigue life of the crankshaft,significantly reduce the extent of damage and fatigue risk area near the crank end,and is conducive to improving the fatigue life and anti-damage ability of the crankshaft.