The invention discloses a road greening trimming device for municipal engineering, and relates to the technical field of greening trimming devices. The road greening trimming device comprises a vehicle body, a vertical sliding rod is fixedly mounted at one side of the vehicle body through a base block, a movable column is slidably mounted on the vertical sliding rod through a sliding block, and a fixed flat plate is fixedly mounted at the top end of the movable column; and a transverse sliding sleeve is rotationally installed at the top side of the fixed flat plate through a rotating column, a transverse sliding rod is slidably installed on the transverse sliding sleeve, and a U-shaped fixed frame is fixedly installed at one end of the transverse sliding rod. The road greening trimming device is reasonable in structure and easy to operate; a motor rotates, an L-shaped driving rod drives a movable serrated knife to reciprocate along a fixed serrated knife, and therefore the continuous shearing function is achieved; and through the mechanism arrangement, multi-dimensional adjustment of the height, the inclination angle, the horizontal distance to the vehicle body and the like of a shearing mechanism is achieved, and in the process that the vehicle body moves along with rollers, trimming of a parterre type green belt is completed.