There exist high gas and serious spontaneous combustion tendency at the same time in many coal mines in china.When the gas is pumped

it is easy to cause the spontaneous combustion of residual coal.So it is very important to observe the gas in the goaf to prevent coal spontaneous combustion.In this paper

the least squares method is used to analyze the gas of high drainage tunnel lying in the 8403 working face of No.5 coal mine of Yangquan Coal Co.

Ltd

Shanxi province.The CO concentration variation curve is obtained by fitting.The fitting method and fitting effect are analyzed.The results indicate that the fitting based on the least squares method is feasible and valid.Combined with the actual conditions of the working face

the reasons of having higher CO concentration in the high drainage tunnel and choosing the high drainage tunnel gas to predict the spontaneous combustion in the goaf are analyzed.The results show that spontaneous combustion can be foreseen more early by analyzing the gas of high drainage tunnel.At last

the correlations between the CO and the CO2 and between the CO and the O2 are analyzed by utilizing the related coefficient.The accuracy of using CO to predict coal spontaneous combustion in the goaf is proved.