Abstract: Abstract：In the process of mine production and transportation, we will sometimes ignore the influence of air temperature in the mine working face on belt’s breaking strength, so that the belt breaks and the transportation of coal flow system breaks off, which not only brings hidden danger to safety production in coal mines, but also seriously affects economic benefits. We use rank sum test from statistical testing methods to analyze and investigate the transportation condition of belt conveyors in certain mine air temperature. Trough data calculation and arrangement of belt’s breaking strength in the mine working face, It is concluded that air temperature in the mine working face in not overrun and overrun of two kinds of cases,the belt’s breaking strength has a significant difference.The method not only can judge safety stability of the working face, but also provide stricter indicator for management of safety production in coal mines to ensure that the process of coal transportation becomes faster and safer.