Abstract: Because passive filters can only eliminate specific harmonics, traditional active power filters can only be used in the low-voltage distribution network due to low voltage withstand level, and the compensation accuracy is limited due to low level, the active power filter based on modular multilevel converter（MMC） is selected as the research object. Meanwhile, a nonlinear passive control strategy based on port-controlled Hamiltonian with dissipation（PCHD） model is proposed by using the passivity of MMC-APF. The passive model based on PCHD is deduced through the mathematical model of MMC-APF system. The passive controller of the system is designed by means of interconnection and damping distribution. The system modulation signal is obtained by means of sub-block capacitance, circulation control and passive control. The simulation results show that the passive control strategy based on PCHD model designed in this paper can control the system under lower harmonic standards, and has better harmonic compensation performance and faster response speed than the traditional PI control strategy.