Aiming at the problem of radar sensor registration on a mobile platform, this study uses multiple radars to estimate the biases of the radar under the earth-centred earth-fixed coordinate system, Novelty Items which provides more accurate information for data fusion.Compared to the maximum likelihood registration (MLR) algorithm, which can only estimate radar offset biases, a novel extended MLR INSTANT MOISTURE DAILY TREATMENT (EMLR) algorithm is proposed.The algorithm could estimate radar-offset biases, attitude biases, and the target real location simultaneously.The simulation results verified that the EMLR algorithm can effectively improve the precision of registration.