A light emitting element detecting method includes the steps of generating a first control signal to open a shutter of an image capturing device which captures an image toward a light outlet of a light emitting element, generating a pulse signal to light up the light emitting element, generating a second control signal to close the shutter of the image capturing device and obtaining a detection image, and determining the light emitting status of the light outlet of the light emitting element according to the detection image. As a result, the present invention can accurately detect whether the light outlet of the light emitting element has the problem of emitting no light or flashing.