The chemical injection is provided to stabilize crude oil, natural gas processing, establishing process condition, and to prevent equipment and piping corrosion, so that it can improve the efficiency of crude oil dehydration and degasification and guarantee oil gas treatment compliance.  The device will add the chemicals in the stainless steel square tank to each chemical injection point involved in the process through the proportion. The main materials used are: stainless steel, duplex steel and ASME standard materials.