Back and forth hand power middle transmission T type four-wheel drive mower is suitable for the grassplot in farm and pasturing area, mountain area and foothill area. It is used to finishing lawn, harvest pasture, trim garden and pack up shrub and so on. The engine is four- stroke, air-cooled gasoline engine which is started by rebound starter and it can transmit smoothly without energy loss. The output of gearbox uses the special clutch and no gear shift. The blade is driven by sliding slot which is driven directly by the roll installed on eccentricity wheel crank. The eccentricity wheel organ connect with power output belt pulley which comes from the front end of chassis transmission box through one belt transmission. It adopts the combined geared clutch. The clutch controls the moving blade and switch controls the accelerograph. Emergency flameout switch is placed on the handle which can be adjusted in the vertical direction. The blade is made of the special chrome steel which is able to bear for long time. The clearance can be adjusted by bush of pressure plate. The blade guide is accurate and steady. In order to increase adhesion force, the tyre use the type shape. Safety cover is on the transmit mechanism, so it is more safe. This machine has the characteristics of wide use, smooth running, low power consumption, good cutting quality and no stop of reamer.