The invention discloses a continuous vehicle speed detection method based on laser radar, relates to the fields of a laser radar speed detection technology and a vehicle speed detection technology andsolves the problems that vehicle and non-vehicle objects cannot be classified through 2D laser radar detection and the cost of high-cost 64-wire 3D laser radar is too high in existing technologies for performing vehicle speed detection through laser radar. A 16-wire laser radar is adopted for continuously acquiring road scene data of traffic lanes, then, vehicles are associated with a method forassociating vehicles in multi-frame data, the vehicle speeds are detected, the problem that measurement is affected due to frame loss of the laser radar is completely solved, and the problem that measurement is affected due to mutual shielding of vehicles is also solved. The method realizes measurement of continuous speed change curves of vehicles and has great significance in further analyzing vehicle behaviors. The method can be applied to various vehicle speed measurement places in the traffic engineering.