The invention discloses a municipal road traffic marking line spraying device. A movement idler wheel at the right end is fixedly connected with a crankshaft, the left end of the crankshaft is fixedlyconnected with a drive shaft, first bevel gears are fixedly connected with the two sides of the drive shaft, second bevel gears are fixedly connected with driven shafts, and the upper ends of the driven shafts are rotationally connected a transverse board through bearings and fixedly connected with gears; and gears are engaged with gear rings, the gear rings are fixedly connected with a main rotary shaft, the upper end of the main rotary shaft is rotationally connected with the top of a device body, the lower end of the main rotary shaft is rotationally connected with the transverse board, alead screw is sleeved with the inner portion of the main rotary shaft in a clearance mode, and the upper end of the lead screw is rotationally connected with the upper wall of the device body througha bearing. By the adoption of the device, stirring boards are driven by the drive shaft to rotate and swing up and down at the same time so as to stir paint contained in the upper portion of the device body, the crankshaft drives a piston board to repeatedly move up and down to achieve automatic spraying, the automation degree is high, the traffic marking line spraying efficiency is greatly improved, and labor is saved. The device is reasonable and applicable in structural design, high in work efficiency and capable of achieving an even stirring and mixing function in the paint working process.