The invention discloses a laser and microwave hybrid transmission system, and belongs to the technical field of the communication. For the disadvantages of the prior art, a first tunable semiconductorlaser is connected with a d port of a second 3dB coupler, a f port of a second 3dB coupler is orderly connected with a first photoelectric detector, a high-pass filter, a second microwave amplifier,and a microwave transmitting antenna; any waveform generator, a first microwave amplifier and an intensity modulator are orderly connected; a second tunable semiconductor laser is connected with the intensity modulator; the intensity modulator is connected with the a port of the first 3dB coupler, the b port of the first 3dB coupler is connected with the e port of the second 3dB coupler, the c port of the first 3dB coupler is orderly connected with an optical amplifier and a laser transmitting antenna; a microwave transmitting antenna and a microwave receiving antenna correspondingly transmitsand receives the signal, and the microwave receiving antenna is connected with a wave detector; the laser transmitting antenna and the optical receiving antenna correspondingly transmits and receivesthe signal, and the optical receiving antenna is connected with a second photoelectric detector.