The present application discloses a displacement filling method and a related device, the method comprising: at t n‑2 moment, t n‑1 moment and t n The vehicle is recognized as the second vehicle by the point cloud of the first vehicle at all times; the t corresponding to the identification of the second vehicle n Time point cloud data to obtain the relative displacement s between the second vehicle and the first vehicle n ;according to the relative displacement s n and fill in the displacement Δs to obtain the actual relative displacement s between the second vehicle and the first vehicle n ’; filling displacement Δs is based on the corresponding t of the second vehicle n‑2 Time point cloud data, t n‑1 The relative displacement s between the second vehicle and the first vehicle obtained by point cloud data recognition at each moment n‑2 , relative velocity v n‑2 , relative displacement s n‑1 and the relative velocity v n‑1 obtained by the operation. It can be seen that based on the relative displacement s n‑2 , relative velocity v n‑2 , relative displacement s n‑1 and the relative velocity v n‑1 , pre-computing t n The filling displacement Δs that needs to be filled after point cloud data recognition at any time, using its relative displacement s n The actual relative displacement s obtained by filling n ’, reduce the delay difference and avoid the problem of inaccurate lag.