The invention relates to an articulated hillside tractor with a cascaded efficiency power transmission system. A main machine includes power, a clutch, an efficient power transmission system, a cockpit, a front profiled hinge, a rear profiled hinge, a main bridge and a host walking system; an auxiliary machine includes an auxiliary bridge, a rack, a lifter, a steering arm and an auxiliary walking system; a high-power box, a gearbox and a combiner box are connected in series so as to form the efficiency power transmission system; the high-power box includes an input shaft, an input end gear pair, a power output shaft, a front gear pair, an outgoing end gear pair and a front power shaft; a universal gearbox is adopted as the gearbox; and the combiner box includes a power take-off gear pair, a power take-off shaft, a planetary gear train, a differential large gear, a front shaft, a rear shaft, an inter-shaft differential mechanism, a bevel gear pair, a main bridge differential mechanism, a main bridge half shaft, a hydrostatic transmission or a motor and a motor gear. The articulated hillside tractor has the advantages of front and back power interfacing, power stepless speed change, chassis exchange and simple production, and can assist in preventing the burnout of a transmission part.