Abstract: A mechanical-thermal cooperation method for activating the coal gangue was studied by means of X-ray diffraction analysis(XRD), scanning electron microscope(SEM) examing, laser particle analysis and macro mechanical property test. The results shows that the decomposition and change to glassiness of argillaceous minerals in coal gangue, when it has been heated, is the source of activity of calcined coal gangue. And the high or low of temperature will greatly affect the activity, for the coal gangue produced in Beijing there is an optimum temperatare of 900℃. On the other hand, the grinding time for calcined coal gangue will also greatly effect the activity, the time longer, the surface area larger, and then activity larger. However, when the grinding time reaches a ceratain valum, the grinding efficiency will become obviousely lower. So, for the coal gangue produced in Beijing, there is also an optimum time of 15 min.