The invention discloses an improved fixed-frequency hysteresis current control method and a circuit based on a control-type soft switch. The switching frequency of a control-type soft switch is set to be the same with the frequency of triangular carrier, the tracking trajectory of inductive current is obtained according to a formula (shown in the description), the current error is compared according to hysteresis control in order to control the on-off of a power switching tube, and improved hysteresis modulation is thus formed for sliding mode control. Triangular carrier control and hysteresis current control are combined, and the switching frequency is fixed on the basis of zero-voltage switching-on of the power tube, so that the output frequency of an inverter is more fixed, and the design of a filter is facilitated. The control method of the invention has the advantages of lower switching loss, high power density, high efficiency, low cost, and the like, and is especially suitable for lower-power application occasions.