A garbage data scrubbing method includes obtaining an input/output (IO) busy/idle status of a terminal at a current moment, where the IO busy/idle status includes a busy state and an idle state. When the IO busy/idle status of the terminal at the current moment is the idle state, a discard message is delivered to a storage device, where the discard message includes an initial address and a size of to-be-scrubbed physical space in the storage device, and where the discard message is used to unbind a mapping relationship between a physical address of the to-be-scrubbed physical space and a corresponding logical address.