Abstract: This paper introduces the design and performance test process of a 22-inch single cold head cryopump. The traditional structure is simplified to reduce the processing difficulty of the baffle and cryopanel. Moreover, simulation and modeling of structures such as the anti-radiation shield, baffle and cryopanel are carried out based on heat conduction and radiation models. Among them, the maximum difference between the measured data (92.8 K) and the simulated data (93.9 K) on the baffle is 1.1 K; the simulated values of radiation heat leakage for the primary and secondary stages are 52.339 W and 0.516 W respectively. Relying on the cryopump performance test platform, systematic tests are conducted on the cooling characteristics and pumping capacity of the prototype. Specifically, it takes 177 minutes for the cryopump to cool down from 290 K to 20 K, with the stable temperatures being 65 K for the primary stage and 4.5 K for the secondary stage; the pumping speeds for nitrogen, argon and hydrogen are 13520, 11154 and 16224 L·s⁻¹ respectively; the pumping capacity of argon is 13475 Std·L (at 273.15 K and 1 standard atmosphere). All indicators meet the design requirements and reach the equivalent level of the foreign competitor.