Abstract: A phase-shift soft-switching full-bridge welding inverter is proposed based on peak current control.By a DC block capacitor in series with the primary of transformer,and a saturable inductor in series with the lagging-leg switch,the zero-voltage turn-on for the leading-leg can be achieved due to the energy stored in the output inductor and the leakage inductor,the zero-current turn-off for the lagging-leg can be achieved due to the resonance between the DC block capacitor and the leakage inductor,and the reverse current is blocked by the saturable inductor,the diodes in the secondary circuit can be turned off naturally due to the current doubler rectifier.Hence,the center-tap in the transformer is not needed,and only half of the output current is carried by the secondary winding of the transformer,and the output inductor can be integrated on a single core,the external characteristics of constant current is obtained by peak current control mode.The principle of operations was also discussed.Finally,a 2.5 kW arc welding inverter was made,and the relevant experimental results were also presented.