Abstract: In order to improve the precision of the microseismic location, the quadratic optimization of mining microseismic source location has been researched through using MATLAB software and its toolbox in this paper. First, the microseismic location problem is boiled down to solving linear equations using traditional mathematics method and a Four-Four combined positioning model is set based on a multiple sensors; second, the k-means clustering method is applied to optimize the positioning results. Two classes—core cluster and peripheral cluster are set to processing those data. When it meets the principle of heart knee point and noise migration distance, the circular will stop and the final result will be solved. The result of field test shows that the optimized results are in close proximity to the real source; the distance between those is about 12.08 m (x：1.8 m，y：2.83 m，z：11.6 m). This method is simple and easy to operate, and the precision has been improved compared with the single positioning method.

Key words: microseismic location, Four-Four method, quadratic optimization, cluster analysis