The invention discloses a device for optically generating radar pulse compression signals. The device comprises a laser, a coding signal generator, a microwave signal generator, a polarization multiplexing double-parallel Mach-Zehnder modulator, a direct-current power supply, a photoelectric detector, a polarizer and a polarization controller; and, by utilization of the frequency-shifting characteristic and the phase modulation characteristic of the polarization multiplexing double-parallel Mach-Zehnder modulator, after being coupled through the polarizer, polarization orthogonal modulated optical carrier signals and unmodulated optical first-order sideband signals output by the polarization multiplexing double-parallel Mach-Zehnder modulator are detected through the photoelectric detector, so that phase coded or linearly frequency-modulated radar pulse compression signals can be generated. On the basis of the integrated modulator structure, the device disclosed by the invention is simple in system composition and steady in performance; and, the following disadvantages can be overcome: the traditional manner of generating pulse compression signals in the electric domain is limited by the rate and the bandwidth of an electronic device; high-frequency signals are generated difficultly or cannot be generated; the time-bandwidth product is limited; the reconfigurability and the frequency adjustability of the system are poor, etc.