A mounting method of an external storage device based on a dual system of a same communication terminal, wherein the dual system comprises a first operating system and a second operating system, the mounting method comprising: transmitting a mounting request to the second operating system through the first operating system when the external storage device is mounted on the second operating system; unmounting the external storage device that is mounted on the second operating system when the second operating system receives the mounting request; mounting the external storage device on the first operating system when the second operating system unmounts the external storage device successfully; the mounting method being characterised in that: the step of transmitting a mounting request to the second operating system through the first operating system comprises: transmitting the mounting request to a communal unit of the dual system through the first operating system; forwarding the mounting request to the second operating system through the communal unit of the dual system; when the second operating system receives the mounting request, the step of unmounting the external storage device that is mounted on the second operating system comprises: unmounting the external storage device that is mounted on the second operating system and transmitting an unmounting result to the communal unit of the dual system, when the second operating system receives the mounting request; forwarding the unmounting result to the first operating system through the communal unit of the dual system; when the second operating system successfully unmounts the external storage device, the step of mounting of the external storage device on the first operating system comprises: mounting the external storage device on the first operating system, when the first operating system receives the unmounting result representing that the external storage device is unmounted successfully. transmitting a mounting request to the second operating system through the first operating system when the external storage device is mounted on the second operating system; unmounting the external storage device that is mounted on the second operating system when the second operating system receives the mounting request; mounting the external storage device on the first operating system when the second operating system unmounts the external storage device successfully; the mounting method being characterised in that: the step of transmitting a mounting request to the second operating system through the first operating system comprises: transmitting the mounting request to a communal unit of the dual system through the first operating system; forwarding the mounting request to the second operating system through the communal unit of the dual system; when the second operating system receives the mounting request, the step of unmounting the external storage device that is mounted on the second operating system comprises: unmounting the external storage device that is mounted on the second operating system and transmitting an unmounting result to the communal unit of the dual system, when the second operating system receives the mounting request; forwarding the unmounting result to the first operating system through the communal unit of the dual system; when the second operating system successfully unmounts the external storage device, the step of mounting of the external storage device on the first operating system comprises: mounting the external storage device on the first operating system, when the first operating system receives the unmounting result representing that the external storage device is unmounted successfully. the step of transmitting a mounting request to the second operating system through the first operating system comprises: transmitting the mounting request to a communal unit of the dual system through the first operating system; forwarding the mounting request to the second operating system through the communal unit of the dual system; transmitting the mounting request to a communal unit of the dual system through the first operating system; forwarding the mounting request to the second operating system through the communal unit of the dual system; when the second operating system receives the mounting request, the step of unmounting the external storage device that is mounted on the second operating system comprises: unmounting the external storage device that is mounted on the second operating system and transmitting an unmounting result to the communal unit of the dual system, when the second operating system receives the mounting request; forwarding the unmounting result to the first operating system through the communal unit of the dual system; unmounting the external storage device that is mounted on the second operating system and transmitting an unmounting result to the communal unit of the dual system, when the second operating system receives the mounting request; forwarding the unmounting result to the first operating system through the communal unit of the dual system; when the second operating system successfully unmounts the external storage device, the step of mounting of the external storage device on the first operating system comprises: mounting the external storage device on the first operating system, when the first operating system receives the unmounting result representing that the external storage device is unmounted successfully.