Abstract: In order to set up the quantitative relationship between the specific surface area increased and the CO production value during the coal crushing process, and explain the influence law of the low temperature oxidation occurred from coal after the coal crushed to the CO production value.A full closed type coal sample crushing test instrument, gas chromatography, specific surface area and pore size ana-lyzer and curve fitting method were applied to the experiment study on the quantitative corresponding relationship between the specific sur-face area increased value and the CO production value during the coal crushing process under the oxygen free environment and aerobic en-vironment.A mathematical derivation of the quantitative relationship between the coal specific surface area increased and the CO produc-tion value under the aerobic environment was established and the influence law of the low temperature oxidation to the CO production value was mastered. The study results showed that under the oxygen free environment, there was no quantitative coresponding relation betweenthe coal specific surface area and CO production value. Under the aerobic environment, during the coal crushing process,a low tempera-ture oxidation would be occurred and then CO produced. The fitting curve of the coal specific surface area and CO production value would be a second parabola. Within a certain scope, with the coal specific surface area increased, CO production value would be steadily increased and would be in stable finally.