Abstract: Objective The aim is to explore the effects of different welding processes on the microstructure and properties of high manganese steel welded joints, and to find suitable welding processes for high manganese steel. Methods The effects of SMAW, SAW and GMAW processes on the microstructure and mechanical properties of domestically produced ultra-low temperature high manganese steel welded joints are studied by using scanning electron microscopy (SEM), optical microscopy (OM), X-ray diffractomer (XRD) and other methods, as well as through experiments such as room temperature tensile testing, low temperature impact testing and microhardness testing. Results The results show that, under the three welding process conditions, the microstructure of the heat affected zone is austenite with a small amount of inclusion particles, the grains near the fusion line are coarse and narrow, the weld microstructure is columnar.The fracture positions in the tensile testing are all welds. The maximum tensile strength of SAW, SMAW and GMAW are 775.4 MPa, 686.7 MPa and 749.2 MPa. The tensile properties meet the engineering requirements. The impact absorbed energy of SAW weld at −196 ℃ is 80.7 J, the impact absorbed energy of GMAW weld at −196 ℃ is 71.7 J, and the impact absorbed energy of SMAW weld at −196 ℃ is 64.0 J. The impact fracture surfaces are all ductile fracture. The minimum microhardness of the welded joints for three welding processes are all located at the center of the weld. The peak hardness of the weld center is the smallest in SMAW, the larger in SAW and the largest in GMAW. Conclusion The comprehensive performance of SAW is the best, followed by GMAW, and SMAW is the worst.