ing at the photoelectric performance measurement for GaInP/InGaAs/Ge triple-junction solar cells used in aerospace, we introduce the solar simulator method and the high altitude balloon method. The measurement principle of the solar simulator method and the traceability chain of key values are described. Based on the dual light source steady state solar simulator and the spectral mismatch analysis, the photoelectric performances of the GaInP/InGaAs/Ge triple-junction solar cells are measured, and the key parameters such as short circuit current, open circuit voltage, maximum power and their corresponding temperature coefficients are obtained. In addition, we introduce the high altitude balloon calibration method. The GaInP/InGaAs/Ge triple-junction space solar cells are carried by the Helium balloon to arrive at the altitude higher than 35 km and their photoelectric performances under high altitude natural sunlight are measured. Simultaneously, their current-voltage characteristic data and the real-time temperature data are collected. After temperature correction, the data collected under high altitude natural sunlight is compared with that by the solar simulator method. The results show that the maximum relative deviations in the short circuit current, open circuit voltage and maximum power are 2.61%, 2.13% and 1.63%, respectively. It means that there is a good consistency between these results of the two measurement methods.