In view of problems that existing emulsion concentration detection methods are greatly affected by temperature and cannot be measured in real time and tracked and sampled throughout the entire process, on the basis of traditional density method, an on-line detection system of mine emulsion concentration was designed. The system monitors real-time status information of emulsion through tension sensor, temperature sensor and liquid level sensor embedded in storage tank and sends it to DSP control terminal. The DSP control terminal solves the current emulsion concentration based on principle of density method and uploads it to the host computer to achieve real-time on-line detection function. Temperature compensation technology is used to reduce measurement error at different temperatures, FIR digital filtering technology is used to filter the vibration interference caused by the sensor bracket and box, and gradient descent algorithm is used to correct the tension sensor parameters to improve measurement accuracy. Experimental results show that the system can realize real-time and on-line detection of mine emulsion concentration, and the maximum error between the detection value and the standard value is 1.5%, which meets the requirements of coal mine production.