Abstract: CAFe facility, located at Institute of Modern Physics, Chinese Academy of Sciences, is an experimental prototype of superconducting proton linac. The beam experiment research surrounding this facility can lay a foundation, and provide experience for the design and research of accelerator of Accelerator Driven Subcritical System(ADS) in the future. A special beam DUMP and a corresponding beam collimator before it are needed to achieve CAFe's 10-mA beam goal. In this paper, the systematic design and calculation of the beam collimator are carried out for the development of CAFe DUMP. To ensure that the residual radioactivity after beam bombardment is within a reasonable range, Material of Al6063 is used for the collimator inner element facing the beam. Based on Monte Carlo particle transport simulation, radionuclides and residual dose analysis were carried out. The results show that the peripheral dose of the collimator will be on the order of 100 μSv/h, which is acceptable during decommission. The temperature distribution and temperature raise of the collimator under various beam conditions are simulated with ANSYS code. It is demonstrated that the collimator can safely remove heat from beam power under normal conditions and protect the device under abnormal conditions effectively. The results show that the collimator meet the design requirements of beam halo removal. During the CAFe high power beam commissioning, the collimator and the DUMP were operated normally, with beam current monitoring value consistent with the designed parameters. It proved that the collimator realized the function of beam halo removal, beam parameters diagnostics and DUMP protection.