In order to explore the influence of local high radiation on short-circuit current of multi-junction solar cell in concentrated photovoltaic module with Fresnel lens as the concentrator, the diameters of the high bright spot of Fresnel lens were measured so as to measure the short-circuit current of the GaInP/GaInAs/Ge triple-junction solar cell with different sizes of lens under different local illumination areas. And the experimental results were analyzed by using circuit network model. The results show that the short-circuit current is independent of the area of bright spot, and the current along the optical axis changes synchronously with radiation when the small size Fresnel lens is focused. When the size of lens increases to a certain extent, high radiation presents inthe center of solar cell, and the current is limited by peak tunneling current, which is reflected as the decrease of short-circuit current at the focal plane. Putting the solar cell on both sides of the focal plane canalleviatethe local high radiation, and the short-circuit current can be increased by 8.0%.