The utility model discloses a round pin axle mounting structure, include: the round pin axle, the round pin axle is including installed part and connecting piece, the installed part passes the fixing base and stretches out, installed part and connecting piece structure as an organic whole wherein set up spacing step between installed part and the connecting piece, the one end of round pin axle through fixed seat sets up the fabrication hole, set up the clearance around the fabrication hole. The utility model discloses a set up spacing step, the connecting piece card that will sell the axle is in the fixing base outside, and the installed part passes the fixing base and stretches out a segment length, makes things convenient for the later stage to revolve anchor and decides, through setting up the fabrication hole on the installed part, rivets soon the fabrication hole through spin riveting machine, to scattering the joint all around on the fixing base around the fabrication hole, realizes the installation of round pin spool and fixing base. The assembly uniformity is good, and surperficial rounding is smooth, and intensity is big, and the round pin axle is firm moreover, and the pulling -out force can reach more than the 300N, very big assurance the reliability of assembly.