Abstract: in order to improve the onine detecion accuracy of the emulsion concentration.the paper stated the stucy statuson theonline detection tfechnology of he emulsion concentration.comparison analysis on the technical principle,detecion plan and advantage and disadvanage of the conventional dete ction method and summarized the industiaized status of the technolog;.T'he paper provided the onine delection method based on a high accurate densimer and had an oulook o the industralized prospects of the method.The resulis showed that the density method with the emulsion concentration sensorcoula have repeated cosistency in the detecton accuracy and measured resuits The stability of the products could have obious advantages.The concentration measured absouite accuracy ofthe density method coud be 0.25% an .10% indicely for Fuchs ME10-4 emusion oil and Geso MS10-5( G) erulsio oi. An underground mine industrial ral waspassed with an excellent effect.