Gasoline saw is generally composed of engine, transmission mechanism, sawing mechanism and so on. During operation, the power drives the saw chain through the traditional mechanism, so that the saw chain continuously moves along the guide plate to cut the wood. Engine: Generally a single-cylinder air-cooled two-stroke high-speed gasoline engine. In order to adapt to the operation of the chain saw in different sawing directions and different positions, the pump membrane carburetor with an oil pump is used to drive the diaphragm pump oil by the pressure pulsation in the crankcase, so that the engine can supply oil normally at any position . In addition, new structures such as transistor non-contact magneto ignition system and one-way valve intake system are increasingly widely used, thereby improving the performance of the engine. Transmission mechanism: including centrifugal friction clutch and reducer. The reducer generally uses a cone-shaped reducer, which is convenient for horizontal and vertical adjustment of the sawing mechanism relative to the machine body to meet the needs of different sawing directions during logging and timber production. Saw-milling mechanism: It is the working part of the chain saw, including driving sprocket, saw chain, guide plate, saw chain tensioning device and wood-inserting teeth. For gasoline saws, the future development trend will be to use new materials, new processes, and new structures to further reduce the weight of the chain saw; reduce noise and vibration, and reduce air pollution to improve operating conditions; add safety protection devices to improve use Reliability and safety, at the same time will continue to improve the new chain saw powered by the rotor engine and remote control.