The invention discloses an oil product quality improver for gasoline, diesel and ship distillate fuel oil. The oil product quality improver comprises: 1) xylene; 2) polyisobutene amine; 3) biphenyl; 4) a cationic fluorocarbon surfactant; (5) phosphate MAX-P16. The oil product quality improver can further comprise triphenyl phosphite. The components of the oil product quality improver provided by the invention are added into 89#, 92#, 95# and 98# 1 gasoline, diesel and ship distillate fuel oil with national standard, and the oil product quality improver has the effects of eliminating deposit in an oil path, an engine combustion chamber and a fuel spray nozzle and eliminating carbon deposit. Mixed gases are combusted at the optimal ignition position of an upper dead point of an air cylinder instantly and synchronously after catalytic reaction, the thrust of a piston is increased by 30 percent or above, preignition is inhibited and detonation is eliminated. The octane value of the gasoline is increased by 3 to 6 units, the cetane value of the diesel is increased by 2 to 3 units, the heat efficiency is increased by 7 percent or above, the power is increased to 10 to 20 percent or above, oil is saved by 10 to 20 percent, and the advantages of energy conservation, environmental friendliness, capability of reducing cost and the like are achieved.