The invention relates to the technical field of radio fix, in particular to a millimetre wave time-division random code phase modulation multi-passage automobile anti-collision radar. The radar of the invention is provided with a time-division and time-sequence asynchronous control to receive / emit signal, and a receive / emit a dual-purpose quasi-light integrated medium lens antenna array, and scans the objects possible to be collided on the warning road surfaces by DSP according to lane scanning wave beam; the road situation photographing, the vehicle speed sensing and satellite positioning GPS data MCU control time-division n-passage random code millimetre wave phase modulation; emission is carried out sequentially by upper frequency conversion, R / T3, frequency doubling and power amplification, R / T2, a circulator, a wave beam switch and the antenna array; echo passes through the antenna array, the wave beam switch, the circulator, the R / T1, low noise high amplifier, subharmonic mixing, middle amplifier and extracts the multi-passage signal DSP which is processed and controlled by MCU; the driving of multi-automobile of adjacent lanes is not disturbed by each other and can be completed simultaneously; the high-performance environment electromagnetic compatible EMC is provided; when a plurality of road barriers are encountered, the orientation, distance and relative speed are determined by DSP restriction virtual warning; three-dimensional panoramic images are displayed by a CRT; the closer the distance of the object is, the higher the resolution is; the object which is closest to the vehicle is recognized; sound and light alarm are carried out when the distance is less than safety distance; when the distance is near to the dangerous distance, the vehicle can intelligently avoid the barrier or reduce the speed or brake; the radar of the invention can make a choice according to the control reference road situation, the vehicle speed and the GPS data.