A user terminal (20, 30), characterized by comprising an input device, a multi-channel selection switch, an application module, a processor, a password processing module embodied as a hardware structure, and either a security IC chip containing information on user's ID and/or banking card or an IC card seat for mounting a security IC chip to be mounted in the IC card seat therein, wherein the multi-channel selection switch is coupled with the input device, the password processing module and the processor, the password processing module is coupled with the processor, and the security IC chip or the IC card seat is coupled with the password processing module; the application module controls the multi-channel selection switch via the processor so as to enable the user terminal (20, 30) to switch between a password input mode and a normal input mode; when in the password input mode, data from the input device are sent to the password processing module, and then sent to the security IC chip or to the IC card seat after being processed by the password processing module, the processor and the application module; and when in the normal input mode, the input data from the input device is sent to the processor for processing, further comprising a state indicator which is coupled with the multi-channel selection switch and used for indicating the current input mode of the user terminal (20, 30) according to the state of the multi-channel selection switch, characterized in that the multi-channel selection switch determines whether the time interval between the two latest continuous switches between the input modes is greater than a predetermined time interval, and when the predetermined time interval is not exceeded, the multi-channel selection switch does not perform the switching. the multi-channel selection switch is coupled with the input device, the password processing module and the processor, the password processing module is coupled with the processor, and the security IC chip or the IC card seat is coupled with the password processing module; the application module controls the multi-channel selection switch via the processor so as to enable the user terminal (20, 30) to switch between a password input mode and a normal input mode; when in the password input mode, data from the input device are sent to the password processing module, and then sent to the security IC chip or to the IC card seat after being processed by the password processing module, the processor and the application module; and when in the normal input mode, the input data from the input device is sent to the processor for processing, further comprising a state indicator which is coupled with the multi-channel selection switch and used for indicating the current input mode of the user terminal (20, 30) according to the state of the multi-channel selection switch, characterized in that the multi-channel selection switch determines whether the time interval between the two latest continuous switches between the input modes is greater than a predetermined time interval, and when the predetermined time interval is not exceeded, the multi-channel selection switch does not perform the switching.