Simple and convenient is what all machines pursue in the process of use. In the production process, as the technology continues to update, various more convenient accessories are produced to help the machine be more convenient to use. Just like a chain saw, with the automatic oil filling device of the chain saw accessories, the refueling of the chain saw is much more convenient and faster. The biggest function of the automatic oil injection device for chain saw accessories is to enable automatic oil injection for short chain saws in the state of manual oil injection. The amount of oil injection can be automatically adjusted according to the speed of the chain saw, and can also be adjusted by air pressure according to the level of lubricating oil concentration. With the automatic oil filling device, it not only solves the long-term troubles caused to the operator by manually filling oil for the chain saw, but also improves the working efficiency of the chain saw and greatly extends the service life of the cutting mechanism of the chain saw. After using this chain saw accessory, the cutting power will obviously increase during operation, which is faster, more convenient, time-saving, labor-saving, safety, chain-saving, chain-saving, chain-saving and chain-saving than the chain saw with manual oil injection. It is understood that the chain saw with the automatic oil injection device saves a lot of sawing time compared to ordinary chain saws, which indirectly can reduce a lot of fuel consumption, and can also reduce the wear and consumption and use costs of other chain saw accessories. 3/8" saw chain