A method, system and device for controlling a door of a railway vehicle are provided. The method comprises: a door control instruction sent by a transponder (30) is received when a railway vehicle draws into the station, wherein the door control instruction is used for determining a door of the railway vehicle at a platform side; and the railway vehicle is controlled to open the door of the railway vehicle at the platform side according to the door control instruction, thereby solving the technical problem that the door of a railway vehicle at the non-platform side may be opened by mistake by a driver due to human factors because the door of the railway vehicle at the platform side is manually opened when the railway vehicle stops.