The invention relates to the technical field of radio positioning, in particular to a millimeter-wave random bi-phase code phase modulation amplitude modulation automobile anti-collision radar. Set the optical integrated dielectric lens antenna and array, DSP scans the beam according to the lane to warn the target that may collide on the road surface, and a broadband noise source generates two random code generators. Random code generator B-symbol amplitude modulation, receiving / transmitting conversion and control trailing edge detection, double random code radio frequency through up-conversion, R / T3, frequency multiplication and power amplifier, R / T2, isolator, antenna transmission; echo through the antenna Array, beam switch, isolator, R / T1, high amplifier, down-conversion, intermediate amplifier, random sequence asynchronous gate, digital intermediate frequency quadrature detector I / Q, digital pulse pressure correlator input DSP and MCU processing control , the radar adjacent lane traffic dense driving coexistence operation without interference, has a high environmental electromagnetic compatibility EMC, DSP suppresses false alarms to determine the target azimuth, distance and relative speed, CRT displays three-dimensional images, and identifies the closest distance to the vehicle The goal is less than the safe distance, sound and light alarm, approaching the dangerous distance, intelligent obstacle avoidance or deceleration, braking, its control refers to the road conditions combined with the current vehicle speed and GPS current position information to make a decision, which significantly improves the driving safety of the car.