Three-point bending fatigue test and fracture micro-analysis are used to study the fatigue performance of typical welded j oints of bogie welding for railway express truck with different as-weldeds（without processing） and different postweld treatments. The results show that the fatigue strength of full penetration T-type welded joint is 146.25 MPa. The fatigue strength of the joint after the polishing of weld toe is 165.75 MPa. The fatigue strength of the joint after the shot blast of weld toe is 180.45 MPa. The fatigue strength of the joint after the polishing + shot blast is 203.75 MPa. Through polishing,shot blast and polishing + shot blast of the weld toe after welding,the stress concentration at the weld toe of the joint can be improved effectively,the surface tension stress at weld toe is changed into compression stress,and the fatigue strength of fully penetration T-type welded joints is improved significantly.