The invention relates to a measuring method and a measuring system for the mixing ratio of combined fuel and the single oil spray quantity of an oil sprayer. The measuring system mainly comprises a temperature controller, a thermograph, a consistent temperature heater, a bracket, a manual oil outlet valve, an oil spraying and heating box, a pressure gauge, an oil sprayer, a gas-oil separator, a manual deflation valve, and the like, wherein the consistent temperature heater comprises the temperature controller and the thermograph and is arranged in the oil spraying and heating box, the manual oil outlet valve is arranged below the oil spraying and heating box, the oil sprayer is fixed at the middle of the upper surface of the oil spraying and heating box, and both ends of the upper surfaceof the oil spraying and heating box are respectively connected with the pressure gauge and the manual deflation valve which is connected with the gas-oil separator. The invention heats the combined furl to enable alternative fuel to be changed into a gas state and then separated from diesel oil in a liquid state by utilizing the different boiling points of the alternative fuel and the diesel oil which are contained in the combined fuel and calculates the mixing ratio of the combined fuel and the single oil spray quantity of the oil sprayer by utilizing a weighing method. In addition, the invention has simple method, convenient use of the system and low cost.