Abstract: In bright environments, sunlight can easily drown out the defect information of photoluminescence (PL) phenomenon of photovoltaic panels, so that the inspection equipment cannot directly perceive the defects. To solve this problem, a detection method based on time domain error was proposed, which could effectively reduce the interference of sunlight in bright environments. In this method, the fast pulse width modulation (PWM) chopping constant current power supply was used to output the high-frequency modulated current signal, the 850 nm light source was driven to output the modulated light to excite the photovoltaic panel, the short-wave linear infrared array InGaAs camera was used to capture the image sequence with modulation characteristics, and the defect information of the photovoltaic panel was extracted from the image sequence by field programmable gate array (FPGA). Experimental results show that the proposed method can effectively detect defect pattern information in the illumination range from 2.9 lx to (12 580±5) lx, and realize the continuous defect detection of photovoltaic panels in bright environments.