The utility model provides an emulsion automatic proportioning device, includes emulsion pump station pump box, emulsion oil drum, vacuum electromagnetic starter, solenoid valve, water pipe and pipette, the emulsion pump station pump box in be provided with level sensor, level sensor is connected with vacuum electromagnetic starter, vacuum electromagnetic starter is connected with the solenoid valve, the solenoid valve is connected with the water pipe, the water pipe is connected with the emulsion pump station pump box, still is provided with pipette and siphon mouths in the water pipe, the pipette is connected with the emulsion oil drum, the beneficial effects of the utility model are that: 1, enable to adopt a hydraulic prop and keep good operating condition constantly, improve hydraulicprop life, reduce the overhaul frequency, 2, reduce post workman's work load, reduce worker intensity of labour, 3, improve emulsion ratio precision, 4, adopt siphon principle, need not provide outside power supply, realize the automatic ratio of working medium.