The invention discloses an all-solid-state Marx generator with a saturable pulse transformer substituting for a gas switch. The all-solid-state Marx generator is used for solving the problems that existing Marx generators are high in charging voltage, non-synchronous in capacitor charging, short in gas switch life or high in magnetic switch saturable inductance, series are hard to increase and the like. The all-solid-state Marx generator is composed of the saturable pulse transformer SPT, Q-grade Marx capacitor and grounding inductor units and a load, the SPT is in an axial symmetric structure, Q-group secondary windings of the SPT serve as a magnetic switch, Q-grade Marx capacitor and grounding inductor units are evenly distributed on the outer circumference of the SPT and are connected with Q-group secondary windings. Each grade of the Q-grade Marx capacitor and grounding inductor units is composed of a Marx capacitor and a grounding inductor. The all-solid-state Marx generator has the advantages of being low in input charging voltage, short in series connection, synchronization and built-up time of the switch, high and repetitive in operation frequency, solid and long in service life, a magnetic core can be reset automatically, and all grades of capacitors are charged uniformly.