Efficient painting device for building wall

The invention discloses an efficient painting device for a building wall. The efficient painting device comprises a moving mechanism, a folding mechanism and a painting mechanism; the folding mechanism is arranged on one side of the moving mechanism; the painting mechanism is rotatably connected to the side, away from the moving mechanism, of the folding mechanism; the folding mechanism comprises rotating seats, a support, a stabilizing rod, a first transmission lead screw, a motor and a moving rod; and the rotating seats are connected to the two ends of one side of the top of the moving mechanism through bolts. The size of the whole device can be changed, so that the device is more convenient to carry; a painting roller can be located at the highest position or the lowest position of the whole painting mechanism, and painting of a horizontal building wall and painting of the bottom of a vertical building wall are achieved; and the painting roller can be extruded through an elastic extrusion assembly, so that