The invention discloses a data storing and processing method, a device and a terminal. The terminal comprises a power supply interface, a storage device, a communication interface and a processing module, wherein the power supply interface is used for being connected with an external power supply for supplying power to the terminal; the storage device is used for storing data; the communication interface is used for being connected with an external device, and is used for providing an interface for the external device to access the storage device; the processing module is used for keeping the power-off state of the terminal and starting the data storing function of the storage device under the condition that the terminal is determined to be in a power-off state and the power supply interface is connected with the external power supply, so that the external device can access the storage device through the communication interface. Through the data storing processing method, the device and the terminal, the problem that the storing function of the terminal can only be used in a power-on state in the prior art is solved, and the convenience in use is enhanced.