The invention relates to a temporary supporting device for roadway drifting. The key technical points of the temporary supporting device for roadway drifting are as follows: a middle support plate is fixedly connected with the upper part of a top beam frame; two side support plates are respectively arranged at two sides of the middle support plate; the support plates are mutually hinged; the sidesupport plates are hinged with the top beam frame through a link mechanism below the side support plates; the top beam frame is also hinged with two bracing cylinders; the other ends of the two bracing cylinders are hinged with a longitudinal connecting beam of the link mechanism of the two side support plates; and a longitudinal connecting beam of a link mechanism below another two side support plates is hinged with a floating cylinder. The lower end of the top beam frame is hinged with the top part of a rack; and the rack is a component of a foldstool with a shape that two supporting feet are crossed. The rack comprises a left L-shaped girder, a right L-shaped girder, a stay bar, a lift cylinder, and an adjusting cylinder. A caterpillar mechanism is connected with the bottom of the rackin a dismountable way; and a road clearing shovel is arranged at the lower part of the front end of the rack. The temporary supporting device for roadway drifting has simple and flexible structure, is safe and reliable, and can adapt to changes of sizes and shapes of roadway roofs in a certain scope.