To solve the problems of unstable inverters caused by power grid disturbances，slow response speed of traditional phase-locked loops (PLL)，and poor phase-locked accuracy resulting in voltage frequency offset and phase errors，a double loop inertial phase-locked loop (DPLL) based on voltage and current double loop control is proposed. Firstly，the working principles and characteristics of the main circuit and control circuit of the three-phase voltage type PWM inverter were analyzed using Clarke and Park coordinate transformation theory，and the control strategy based on this inverter was derived. Secondly，the new structure of DPLL and its parameter tuning strategy for PWM inverters were proposed. Compared with traditional phase-locked loops，the DPLL has better grid synchronization performance under grid disturbances. The double loop control structure (frequency locked loop and phase locked loop) is used to track the frequency and phase of the inverter. Due to the inertia control of phase angle，DPLL has good anti-interference ability，which can effectively reduce the frequency offset and phase error of the inverter. Finally，the feasibility and effectiveness of the newly designed DPLL were verified through simulation analysis.