The invention discloses a subway tunnel construction method and a mobile charging system for the same. According to the method, a storage battery of a subway tunnel traction engine is charged; and a loading storage battery of the subway tunnel traction engine is charged. According to the mobile charging system achieving the above method, a cable supporting device comprises a sliding trolley used for supporting a cable and a slide rail used for supporting the sliding trolley; the slide rail is arranged in the subway tunnel track direction; the connected position of the cable and the cable supporting device is a connection point; the number of the sliding trolley is at least one; and the sliding trolley is arranged on the slide rail in a sliding manner, and is connected with the cable to form a connection point. Due to the subway tunnel construction method and the mobile charging system for the same, the storage battery is charged in use, thus it is not needed to replace the storage battery, and the load of a worker is relieved; and the storage battery of the subway tunnel traction engine can be charged when the subway tunnel traction engine normally works, the problem that construction is interrupted due to charging or storage battery replacing is solved, and the construction efficiency is improved.