The invention provides a hard disk operation state judgment method, which is used for judging the operation state of an electronic device comprising a serial universal input/output port and a hard disk. The hard disk operation state judgment method comprises the following steps: receiving an operation state original signal of a hard disk from a serial universal input/output port, judging whether aprevious operation state original signal of the hard disk is received or not before the operation state original signal is received; when judging that the original signal of the previous operation state is not received before the original signal of the operation state is received; generating an operation state correction signal according to an operation state original signal of a hard disk and anenabling state signal of a serial universal input/output port, and executing a delay program on the operation state correction signal according to preset time to generate and output an operation state judgment signal.