Abstract: In order to realize a remote upgrading maintenance of the coal shearer with the electromagnetic speed control in the fully mechanized coal mining face a nd to complete the functional iteration, taking the Cortex-M3 core as the main controller for the coal shearer with the electromagnetic speed control as an example, the start principle of the BOOT Loader was analyzed, the memory allocation of the upgrading program was customized, the loading and unloading of the consumers softwar e could be realized and the high efficient real time communication protocol was defined. The practical application results of the coal shearer with electromagnetic speed control in the fully mechanized coal mining face of Shanxi Luliang Rongtai Mine showed that the success rate of once software upgrading was over 90% and the softwar e reliable upgrading completed with the multi loadings could highly reduce the maintenance work load of the electromechanical workers in the underground mine.