A memory management method is provided. The method includes storing an acquired first command into a command queue, and setting a command phase value of the first command according to a current command phase, wherein in response to determining that the first command is a flush command, calculating a command phase count value corresponding to the current command phase, and adjusting the current command phase; selecting a new target command from the command queue, and executing the target command according to a target command phase value of the target command and a corresponding target command phase count value, wherein the target command phase count value which is not a preset value is adjusted; determining, according to the adjusted target command phase count value, whether to respond to a host system that an execution of a target flush command corresponding to the target command phase value is completed.