The invention discloses a rear-end resistance early-warning method for vehicle based on a camera and a millimeter-wave radar. The method comprises the following steps that 1, the camera is calibrated;S2, the vehicle is recognized; S3, the relative distances di between surrounding objects and the vehicle, the relative speeds vi of the surrounding objects and the included angle alpha I in the perpendicular direction of the emitting surface of the radar are detected by the millimeter-wave radar, wherein i is the positive integer; S4, sampling points of null objects and invalid objects are removed; S5, sampling points corresponding to vehicles running from a lane in the opposite direction are removed; S6, sampling points corresponding to effective targets are selected; S7, the effective target with the smallest longitudinal distance si is determined as a potential rear-end target; S8, the equation that th=si / V is calculated, and according to the result, different warning signals are transmitted. According to the method, the vehicle sampling points of the null targets and the invalid targets can be removed, the sampling points corresponding to vehicles running from the lane in the opposite direction are removed, front vehicles can be detected and recognized more accurately, a driver can be timely warned, and safety in the driving process can be ensured more effectively.