The invention relates to a device and a method for repairing ground cracks of a
coal mining
loess subsidence area. The method comprises the steps of during repairing, firstly, detecting the depth of all the ground cracks formed on a
coal mining working surface and judging the type; filling the ground cracks with a filler, and arranging grouting pipes and electrodes at the ground cracks; adding a
microorganism bacterial liquid into the grouting pipes, and introducing a
direct current between the grouting pipes and the electrodes; adding a
nutrient solution into the grouting pipes; when the ground cracks are filled with mixed size of the
microorganism bacterial liquid and the
nutrient solution, stopping grouting; and after the injected mixed size is solidified, planting plants on the ground. According to the invention, the method is simple and easy to implement, the method is more environment-friendly through
microorganism grouting, the distribution of microorganism products can be made more uniform through
electric traction, as a renewable matter, microorganisms can be continuously utilized on a large scale, different prevention methods are utilized for cracks in different
coal mining positions, and the limitation of one method is avoided.