With the wide applications of GaInP/GaAs/Ge threejunction solar cells used in spacecraft as a space power supply system, the problem of space radiation damage is widely concerned. The performance of GaInP/GaAs/Ge threejunction solar cells will be degraded by the irradiation of the electrons, protons and other radiation particles or rays in the space radiation environment. In this paper, the research progress of the radiation experiments of GaInP/GaAs/Ge triplet solar cells induced by the electrons, protons and other radiation particles or rays at home and abroad is introduced in depth, and then the research progress of the simulation of radiation damage effect, radiation hardening, and radiation damage prediction of GaInP/GaAs/Ge threejunction solar cells is reviewed. The key problems in the research of radiation damage effect on GaInP/GaAs/Ge threejunction solar cells are summarized. It provides theoretical guidance and experimental technical support for the establishment of the experimental method of radiation damage effect, the analysis of damage mechanism, the prediction of inorbit life and the research of radiation hardening technology of GaInP/GaAs/Ge threejunction solar cells.