Abstract: In order to realize automatic temperature measurement and spontaneous combustion hidden source probing of opencast coal stack, an non- contact tem perature on- line monitoring system of opencast coal stack was designed based on the infrared image technology. The paper introduced function modules, hardware eq uipment and software of designed system. Meanwhile the paper introduced the algorithm principle of temperature correction and inner- heat- source calculation. The re search results showed that the monitoring system could all- weather and non- blind- area detected temperature for opencast coal stacks. The measured results of the te mperature calculation indicated that the coal stack temperature measurement average error of the monitoring system was reduced from 14. 33% to 0. 92% in different w eather. The internal temperature calculation average error was 10. 36%, and satisfied the temperature detecting practical demand. Moreover, the system could compreh ensively analyze temperatures and gave the priority of procession for coal stacks of storage base.