ZCuPb20Sn5 alloy is a cast lead-tin bronze alloy. Due to its high lead content, it has excellent comprehensive properties such as friction reduction and wear resistance, high fatigue strength, good thermal conductivity, and good wear resistance. It is widely used in automobiles, Aerospace industry and other fields. Therefore, this article selects ZCuPb20Sn5 alloy as the research object. By adding rare earth La to ZCuPb20Sn5 alloy solution, the metallographic structure and mechanical properties are observed, and the effect of rare earth La on the microstructure and properties of ZCuPb20Sn5 alloy material is analyzed. The results show that with the increase of La content, the tensile strength, elongation and hardness of lead-tin bronze alloys all increase first and then decrease. Without the addition of rare earth lanthanum, the tensile strength of lead-tin bronze can reach about 241.5 MPa. Adding different amounts of rare earth to the lead-tin bronze alloy can improve the tensile strength and elongation of the alloy. When 0.04 wt.% rare earth lanthanum is added, The strength and elongation reached the maximum. After several experiments, the tensile strength remained at about 267.1, the elongation remained at about 15.13%, the tensile strength increased by about 25.6 MPa, and the hardness remained at about 80 HB, with little increase.