The invention discloses a technology for boiling mixed oil for lubricating a magnesium alloy screw chamber machine. The mixed oil is acquired according to the following steps: weighting raw materials, heating and boiling, mixing and stirring and then fully mixing. The technology is simple and convenient in operation; the problem that ultrahigh temperature lubricating oil is difficult to be coated under normal temperature can be avoided; only one-time coating is required; the boiling process is convenient; the viscosity and the high temperature resistance are effectively unified; the dosage of the lubricating oil is greatly reduced; and the cost is saved.