The invention discloses a municipal green belt trimming device. The device comprises a vehicle body, a green belt trimming mechanism is installed at the position, close to the front side of the vehicle body, of the vehicle body, a scrap collecting mechanism is installed at the position, close to the rear side of the vehicle body, of the vehicle body, and the green belt trimming mechanism comprises a driving air cylinder installation base. A driving air cylinder is arranged at the top of the driving air cylinder installation base, a mounting frame is connected to the top of the driving air cylinder, the two ends of the mounting frame are each provided with a fixing plate, and a guide rod is fixedly connected between the two fixing plates. According to the municipal green belt trimming device, by arranging a first trimming mechanism, a second trimming mechanism and a third trimming mechanism, the left side, the right side and the top of a green belt can be rapidly and efficiently trimmed through the device, and the working efficiency is improved; and by arranging a trimming blade mounting shaft, a driving wheel, a transmission belt and a first driving motor, the trimming mechanisms are conveniently driven, the power effect is well, and branches and leaves of the green belt are prevented from clamping the trimming mechanisms.