Organo-halide perovskite solar cells (PSCs) are lightweight and low cost, and they offer high power conversion efficiencies. PSCs have proven to be useful in terrestrial applications. In addition, they are particularly attractive for space applications because they can offer a higher radiation tolerance than GaAs and Si solar cells. This paper evaluates the damage coefficient for minority-carrier diffusion length K L of perovskite crystals after 1 MeV electron irradiation by time-resolved photoluminescence measurements to investigate the reason for their high radiation tolerance. Results show that perovskite crystals have a lower damage coefficient K L than that of InP crystals with a high radiation tolerance. On the other hand, first-principles calculations indicate that the displacement energy of perovskite crystals is as low as that of Si, which does not have a high radiation tolerance. The present results suggest that the annealing effect occurs for PSCs at room temperature.