The invention discloses a software control system and method for soft start of an inverter, comprising a soft-start control unit and a DC power supply module which is connected in turn, a DC power supply module which is connected in turn, and a DC power supply module which is connected in turn. DC convert unit and DC-AC inverter unit, said DC-bus voltage outer loop and the inductor current inner loop of the DC converter unit pass through the first PWM module and are connected with the DC-DC conversion unit is connected,The capacitor voltage outer loop and the load current inner loop of the ACinverter unit pass through the second PWM module and are connected with the DC-AC inverter unit, and the soft start control unit comprises a sampling unit and a timing unit; The invention also discloses a software control method for soft start of an inverter. The invention is more safe and reliable than a single duty cycle soft start mode, and the start time length can be flexibly adjusted withoutadding additional hardware soft start circuit, thereby effectively protecting important devices and improving system reliability.