Abstract: The input current of three-phase current type PWM rectifier (CSR) is pulse in the rectification process, and the filter is usually added to the AC side to suppress the harmonics. However, in the weak current network, the grid impedance cannot be ignored, which makes CSR couple through the filter, thereby causing resonance. In this work, the stability of three-phase current source PWM rectifier in weak power grid was studied, and an active damping control strategy was proposed for the resonance of CLC filter. At the same time, influenced by the grid impedance and node voltage in weak current networks, the resonance problem of multiple CSRs coupled in parallel is much more serious. Therefore, the input-output coupling matrix is established to analyze the system resonance problem. Finally, the effectiveness of the control method herein is verified by the simulation and experimental results.