A novel pulse compression diode capable of generating high-voltage, picosecond pulses is introduced. The design concept and technical means of the novel diode based on semi-insulating gallium arsenide (SI-GaAs) materials are described, followed by the presentation of its static characteristics with three unique operating states. Typical output rise time for the novel diode with self-breakdown is limited to a few nanoseconds (1–2 ns). The basic physical mechanism affecting the fast conduction of the device is then analyzed, and the electrode structure is optimized as a consequence. Finally, a test circuit with a MOSFET as a preswitch is used as an example to verify the compression characteristics of the modified device. The experimental results show that the pulse front is sharpened from 32 ns to 853 ps and the full-width at half-maximum (FWHM) is sharpened from 120 to 2.1 ns by the pulse compression diode without extra triggering. Lifetime measurement experiments were conducted at a pulse repetition frequency of 100 Hz, revealing no instances of switch failures or malfunctions. The novel pulse compression diode has great potential for various applications, including in national defense, industrial, and medical sectors, due to its fast response, long lifetime, high reliability, and ease of series–parallel connection.