Abstract: High temperature chemical extract method can be used to separate ²⁰⁹Bi and ²¹⁰Po in bismuth target after reactor irradiated. Two kinds of metal bismuth targets are designed. The MNCP program is used to simulate the neutron flux and nuclear heating in the CARR reactor, and the heat transfer of the two targets is calculated theoretically. The metal bismuth target is welded by argon, and the tightness of the welded target is checked. The results show that the maximum neutron flux rate of the two kinds of targets at the full power of 60 MW in the CARR reactor is 5.21×10¹⁴ n/cm²·s, the total heat output of the target is 1 707 W and 2 220 W respectively, and the center temperature of the targets is 163.5 ℃ and 191.8 ℃ respectively after heat transfer calculation, which is lower than the melting point of bismuth (271.3 ℃). The leakage rate of the welded target is less than 3.2×10^-9 Pa·m³/s. Bismuth target can be used for the preparation of ²¹⁰Po nuclide by CARR reactor irradiation.