Hot dip Al 22MnB5 sheet and bare sample were welded by GTAW. Microstructure of weld metal and tensile strength were observed and tested, the effects of heat input and surface hot-dipping Al on the heat affected zone and tensile strength were investigated. The result shows that the incomplete quenching zone is composed of ferrite and martensite. The incomplete quenching zone is soft zone and the lowest tensile strength is shown in this zone. Low heat input may cause lack of fusion, or other molding defects; But high heat input would become coarser grain sizes. The optimized heat input of hot dipping aluminized 22MnB5 is at 3800 J/ cm. The preparation of welding has been affected with dipping Al coating and tensile strength of joints have not affected.