The invention provides a transmission box with a gear clutch, particularly a transmission box for transferring power to a hitching gearbox of an agricultural implement, belonging to the components of agricultural machinery. The transmission box comprises a box body, an input shaft, an output shaft, a driving wheel and a driven wheel, wherein the input shaft and the output shaft are mounted on thebox body, the driving wheel is arranged on the input shaft and the driven wheel is arranged on the output shaft. The transmission box is characterized in that a gear clutch is arranged on the output shaft and near to one end outside the transmission box. The transmission box is beneficial to the power distribution of the hitching gearbox of the agricultural implement, can be used in paddy field and upland field, is free from clamp, slide and component damage, runs stably and is less impacted when being meshed.