The invention discloses a split type power speed changer system of a motorcycle, which comprises an engine, a clutch and a speed changer, wherein a crankshaft of the engine inputs power into the speedchanger through the clutch; the speed changer is arranged in an independent speed changer case; and the clutch and the engine are arranged outside the speed changer case. According to the mechanicalproperties of the engine and the speed changer, the invention sufficiently utilizes the other available space of the motorcycle to separate the engine from the speed changer and carries out lubrication in aiming, as a result, the lubrication condition of the speed changer is improved, and the service life of the speed changer can still be prolonged even under the circumstance of large torque; moreover, when the engine is used for driving other machines, the speed changer is directly dismantled, the engine is used for directly driving the machines, the speed changer is not need to output power,a transmission chain is shortened, as a result, the transmission efficiency is increased, and energy is saved; not only is operation simple and convenient, but also the speed changer can be preventedfrom running for a long period, the service life of the speed changer can be prolonged, and therefore use and maintenance costs can be reduced.