The invention relates to a gasoline additive capable of remarkably reducing the precipitate in a gasoline engine combustion chamber. The gasoline additive comprises PIBA with high surface activity, polyether amine, gasoline anti-friction composition, polyether carrier liquid with excellent oil solubility, antioxidant, antirust agent, preservative and emulsion breaker. The weight percentages of the components are as follows: 15 to 30 percent of PIBA, 15 to 30 percent of polyether amine, 2 to 10 percent of gasoline anti-friction composition, 15 to 40 percent of polyether carrier liquid and 20 to 40 percent of cosolventk and other functional agent. When 220 to 550 ppm of the gasoline additive is added into the gasoline for the car sold in the market, the accumulated carbon in an oil nozzle and an air inlet valve can be washed, the precipitate in the gasoline engine combustion chamber can be obviously reduced, the mechanical friction loss can be reduced, and the power can be enhanced. The increment of the precipitate of the car gasoline containing the gasoline clearing agent in the combustion chamber can be reduced by more than 50 percent, the running noise of the machine can be effectively lowered, the power can be obviously enhanced, and an energy-saving and emission-reducing effect can be realized.