Abstract: The methods for mixing ethanol with diesel oil into ethanol-diesel blend fuel were analyzed and compared; the ethanol-diesel blend fuel was made up with biological material as additive. The test on the influence of changing fuel supply advance angle on fuel economy was carried out on single cylinder diesel engine separately using diesel fuel and ethanol-diesel blend fuel. The test result shows that the influence is more sensible when the ethanol-diesel blend fuel is used, and it is beneficial for increasing the fuel economy to reduce suitably fuel supply advance angle.