A novel combined soft switching technique and a novel circuit topologies family of the static inverter with high frequency pulse dc link are proposed in this paper. The topology structure is constituted of isolated high frequency pulse DC link circuit and DC/AC inverter. In order to overcome the duty cycle D of the one transistor forward mode Static Inverter less than 0.5 and the circuit topology of the interleaved forward mode Static Inverter more complicated, the duty cycle extension of high frequency pulse DC voltage is proposed in this paper. The steady operation principle of the active clamp forward mode high frequency pulse dc link static inverter with duty cycle extension and the control strategy of three-state discrete pulse modulation hysteresis current are deeply investigated. The design criteria for the key circuit parameters are gained. By using combined soft switching technique and the duty cycle extension of high frequency pulse DC voltage, a designed and developed 750VA 27VDC/115V400HzAC prototype has the advantages such as high efficiency, high power density, high reliability, high steady precision, fast dynamical response, strong ability of over-load and short-circuit, and low THD of output voltage.