A non-volatile memory device, and a method for accessing the non-volatile memory device are provided. The non-volatile memory device is connected to a host via a bus. The non-volatile memory device comprises an MCU. By independently processing the particular commands using only the auxiliary circuit, the MCU can cease to operate, thus saving power. By setting the bus into power saving mode when the non-volatile memory device is busy, the host and the non-volatile memory device would not communicate mutually, thus, saving power.