A fault detection method for a photovoltaic module, comprising: capturing (S501, S601) an image of the photovoltaic module in a light emitting state; and performing (S502, S603) detection on the photovoltaic module based on the image when a signal-to-noise ratio of the image is maximized, to identify a fault type of the photovoltaic module; wherein the photovoltaic module emits light under action of power supply equipment; wherein the fault detection method further comprises: determining whether the signal-to-noise ratio of the image is maximized; characterized in that the fault detection method further comprises: when the signal-to-noise ratio of the image is not maximized, sending an adjustment instruction to the power supply equipment to adjust a power supply parameter of the power supply equipment until the signal-to-noise ratio of the captured image is maximized; wherein the sending an adjustment instruction to the power supply equipment to adjust a power supply parameter of the power supply equipment specifically comprises: sending the adjustment instruction to the power supply equipment, so that the power supply equipment adjusts the power supply parameter based on the adjustment instruction and a preset curve; wherein the power supply parameter comprises a current parameter, a voltage parameter, or a power parameter; and the preset curve is a preset current curve, a preset voltage curve, or a preset power curve; and; wherein the preset curve is a correspondence that is between different currents, voltages or powers and faults and that is obtained by a tester based on a plurality of tests. capturing (S501, S601) an image of the photovoltaic module in a light emitting state; and performing (S502, S603) detection on the photovoltaic module based on the image when a signal-to-noise ratio of the image is maximized, to identify a fault type of the photovoltaic module; wherein the photovoltaic module emits light under action of power supply equipment; wherein the fault detection method further comprises: determining whether the signal-to-noise ratio of the image is maximized; characterized in that the fault detection method further comprises: when the signal-to-noise ratio of the image is not maximized, sending an adjustment instruction to the power supply equipment to adjust a power supply parameter of the power supply equipment until the signal-to-noise ratio of the captured image is maximized; wherein the sending an adjustment instruction to the power supply equipment to adjust a power supply parameter of the power supply equipment specifically comprises: sending the adjustment instruction to the power supply equipment, so that the power supply equipment adjusts the power supply parameter based on the adjustment instruction and a preset curve; wherein the power supply parameter comprises a current parameter, a voltage parameter, or a power parameter; and the preset curve is a preset current curve, a preset voltage curve, or a preset power curve; and; wherein the preset curve is a correspondence that is between different currents, voltages or powers and faults and that is obtained by a tester based on a plurality of tests. determining whether the signal-to-noise ratio of the image is maximized; characterized in that the fault detection method further comprises: when the signal-to-noise ratio of the image is not maximized, sending an adjustment instruction to the power supply equipment to adjust a power supply parameter of the power supply equipment until the signal-to-noise ratio of the captured image is maximized; wherein the sending an adjustment instruction to the power supply equipment to adjust a power supply parameter of the power supply equipment specifically comprises: sending the adjustment instruction to the power supply equipment, so that the power supply equipment adjusts the power supply parameter based on the adjustment instruction and a preset curve; wherein the power supply parameter comprises a current parameter, a voltage parameter, or a power parameter; and the preset curve is a preset current curve, a preset voltage curve, or a preset power curve; and; wherein the preset curve is a correspondence that is between different currents, voltages or powers and faults and that is obtained by a tester based on a plurality of tests. when the signal-to-noise ratio of the image is not maximized, sending an adjustment instruction to the power supply equipment to adjust a power supply parameter of the power supply equipment until the signal-to-noise ratio of the captured image is maximized; wherein the sending an adjustment instruction to the power supply equipment to adjust a power supply parameter of the power supply equipment specifically comprises: sending the adjustment instruction to the power supply equipment, so that the power supply equipment adjusts the power supply parameter based on the adjustment instruction and a preset curve; wherein the power supply parameter comprises a current parameter, a voltage parameter, or a power parameter; and the preset curve is a preset current curve, a preset voltage curve, or a preset power curve; and; wherein the preset curve is a correspondence that is between different currents, voltages or powers and faults and that is obtained by a tester based on a plurality of tests.