The invention discloses a front power output gearbox of a wheeled tractor adopting a hydraulic clutch. The front power output gearbox comprises a case formed by a left shell and a right shell, wherein the case is provided with an input gear shaft, an output shaft and a hydraulic power unit, a driven gear is arranged on a position on the output shaft, which is close to the output end, the driven gear is engaged with a gear on the input gear shaft, a rolling bearing is arranged between the output shaft and the driven gear, the output shaft is provided with a clutch, a hydraulic oil cylinder is arranged on a position on the output shaft, which is far away from the output end, a cylinder body of the hydraulic oil cylinder is fixed on the output shaft, the output shaft is provided with an output shaft oil passage, the right shell is provided with a shell oil passage, the hydraulic power unit is provided with an oil outlet, the output shaft oil passage is communicated with the shell oil passage, the output shaft oil passage is communicated with an inner chamber of the hydraulic oil cylinder, an oil inlet of the hydraulic power unit is communicated with an external oil passage, and the oil outlet of the hydraulic power unit is communicated with the inner chamber of the oil cylinder through the shell oil passage and the output shaft oil passage. The front power output gearbox has the advantages of compact structure, light weight, high transmission efficiency and strong controllability and maneuverability.