Purpose The performance of CZT in γ-ray and X-ray detection is growing rapidly in these years. However, there are only a few reports on its utilization in α particle detection. Therefore, to study the properties of CZT for detection of α particle, a detection system has been manufactured, and a series of simulations have been done. Methods A22×22×0.7mm3 planarCZTdetector is deployed to detect the α particles from a radiation source containing Am-241 and Pu-239, while COMSOL MultiPhysics and GEANT4 are employed in the simulation of charge collection and interaction between α particles and CZT. Results An energy resolution of 1.47% FWHM at 5.486MeV and 1.32% at 5.157MeV has been achieved. A simulated spectrum has been created, and it is analogous to the one from experiment. Conclusion The experiment results show the potential of CZT in α detection. The simulations are confirmed effective and will guide a better design of the detecting system