Abstract: A solid state high power long pulse generator has been designed and constructed based on the key technologies of magnetic switch, low impedance pulse forming line, and inductive voltage adder, which was verified by single mode operation for peak power of 2 GW. For repetitive operation, a repetitive primary power supply of moderate voltage level was developed, the two stage magnetic pulse compressor was improved from aspects of reset and insulation, the pulsed charging was optimized where the inductive voltage adder was utilized for pulsed voltage step-up as well as for pulse charging and on-line direct current (DC) reset was achieved by reasonable design of reset current path. At present, the experimental results achieved on a dummy load are output pulsed power of 2.1 GW, pulse width of 170 ns, repetitive rate of 20 Hz, operation time of 1 s and good for repeatability. For further improvement, the pseudospark switch would be replaced by serial connected thyristors to accomplish all solid-state design.