A leakage current detection method and apparatus are provided. The method is applied to leakage current detection for a board-mounted component on a printed circuit board assembly (PCBA) board, and includes: providing a fixed voltage for a leakage current input end of a board-mounted component under detection, and connecting a leakage current output end to an inverting input end of an operational amplifier of a resistance testing module, where the resistance testing module includes the operational amplifier and a reference resistor that is connected between the inverting input end of the operational amplifier and the voltage output of the operational amplifier; detecting an output voltage of the resistance testing module; and calculating, based on Ohm's law and according to the output voltage and the reference resistor, a leakage current flowing through the board-mounted component under detection.