The simulation evaluation,standard field test and road test results of gasoline detergent additive are presented.The results show that the gasoline detergent additive can keep engine fuel system clean and possess detergency ability which mainly be made of polyisobutenyl succinimide and uredo urethane compound as detergent,mono end capped polypropylene as synergetic effect additive.It keeps the engine in good working status,thus energy consumption and low waste gas emission are realized.