The aim was to build a user-friendly α-irradiation equipment used for cultured cell study, and to validate its dosimetry and biological efficiency as well. The equipment is composed of α-particle source (241Am), a holder for 241Am, a holder plate for coverslips on which cells grow, and other essential parts. The theoretical average α-particle traversal per cell was calculated based on ideal assumptions. The Geant4 software package was used for modeling and simulating particle traversal. And the dose rate distribution in cells on coverslip was calculated and plotted versus the distance from the center of coverslip. Moreover, the induction of 53BP1 foci, a surrogate marker of DNA double strand breaks and colony formation in WS1 normal human skin fibroblasts irradiated with the α-irradiation equipment were determined. The results showed the disconformity of α-irradiation dose on the coverslip, with the farther the distance from the center of the coverslip, the lower the dose rate. The relative biological efficiency of α-irradiation (RBE) was 1.71 at a SF of 0.5. In conclusion, we have built a user-friendly α-irradiation equipment with a good automation system for cultured cell study, providing better accuracy of exposure time and dose.Cited