Abstract: Thick plate components are widely used in construction machinery and heavy industry. However, the welding groove of thick plate usually has large deviation due to processing and assembling improperly. Groove gap inconsistency, groove angle deviation and misalignment of groove are the typical groove mismatched problems. According to these problems, the corresponding correction measures are proposed respectively. The deviation caused by inconsistent groove clearance can be compensated by adjusting the welding waving parameters. The groove angle deviation can be corrected by jointly adjusting welding parameters and waving parameters. By adjusting the number of weld passes and changing welding current in every weld pass cycles, the misalignment of groove group can be compensated properly. Welding experiment is executed by a welding robot on the workpiece with mismatched groove using the foregoing correction measures. The test results show that the weld is filled well and the appearance of the weld has no obvious defects. Through the observation of weld cross section, the weld beads are arranged orderly without internal defects. The test results show that the groove deviation correction method can widen the applicable conditions of thick plate welded by robot. It also provides basic data for the actual construction of thick plate welded by robot.