In order to meet the requirements of high power density,high performance and low total harmonic distortion (THD) for photovoltaic microinverters, a multi-envelope resonant soft-switch inverter control strategy based on the critical current mode is proposed. Through time-sharing control of switching tubes,the rise and fall time of inductance current is balanced,so as to alleviate zero-crossing distortion. Then,the working mode of the control strategy of multi-envelope resonant soft-switch inverter is introduced in detail,and compared with the traditional critical current mode in terms of soft switch,switching frequency,switching tube loss and inverter efficiency,zero-crossing distortion degree. In order to verify the effectiveness of the control strategy,a 500 W soft-switched single-phase full-bridge inverter is built based on PSIM for open-loop simulation verification. The simulation results indicate that the multi-envelope mode,when compared to the traditional unipolar critical current mode,offers several advantages. These advantages include effective optimization of the zero crossing issue,harmonic filtration leading to reduced THD,and the achievement of zero current switch (ZCS) and zero voltage switch (ZVS) for all switches.