A control method for a storage device is provided. The storage device includes a memory controller and a flash memory. The flash memory includes multiple blocks. The control method includes the following steps. Maintain a state table by the memory controller, wherein the state table records a disturbance count and a last check time of the blocks in the flash memory. Trigger a probe operation on a target block in the flash memory when at least one of the following conditions is met: (a) the disturbance count of the target block is greater than or equal to a disturbance count threshold; and (b) an elapsed time period of the target block is greater than or equal to an elapsed time threshold, wherein the elapsed time period of the target block starts from the last check time of the target block.