A solid-state high voltage pulse power supply with three synchronous output voltages is designed and constructed in this paper. The pulse power supply consists of a fractional-turn ratio saturable pulse transformer and three six-stage Marx generators. The FRSPT not only works as step-up pulse transformers but also as magnetic switches of the Marx generators. All magnetic switches are developed based on two communal cores to achieve a perfect multiple-pulse synchronization effect. The experimental results show that the three output voltages have an amplitude of about 168 kV and a rising time of about 102.6 ns with a 2 MΩ dummy load. The pulse power supply can operate stably at frequencies of 1, 5, 10, and 15 Hz with the synchronization jitters less than 1.5 ns.