The invention discloses environment-friendly and energy-saving gasoline engine lubricating oil, which is composed of composite base oil, a composite oxidation and a corrosion inhibitor, a composite metal detergent, a composite ashless dispersant, a metal passivator, an antirusting agent, an antifoaming agent and a viscosity index improver, wherein the base oil is compounded from poly-alpha-olefin (PAO) and dioctyl sebacate. With the adoption of the gasoline engine lubricating oil, energy conservation, long oil change period, and reduction for waste oil, waste gas and particulate matters are realized, biodegradability is high compared with the traditional lubricating oil, the fuel economy of an engine is improved, the service life of the engine is prolonged, and the generation of oil sludge and carbon deposition in the engine can be inhibited; and the base oil technical requirements of quality grade specifications SG, SH, SJ, SL, SM and SN of gasoline engine lubricating oil, and the performance requirements of multi-grade oil with viscosity grades 0W, 5W, 10W, 15W, 20W and the like can be met.