The invention relates to the technical field of coal mining, in particular to a method and device for optimizing a mining stopping line position with hydrofracture pressure relieving. The method for optimizing the mining stopping line position with hydrofracture pressure relieving comprises the following steps that the geological state of a working face is obtained, and structural data of a roof rock layer is determined; according to the structural data, holes are obliquely drilled towards a roof from a mining roadway and are drilled at a preset distance in the length direction of the mining roadway, and thus a plurality of hydrofracture pressure relieving holes arranged in sequence are obtained; hydrofracture pressure relieving treatment is carried out on multiple preset positions of each hydrofracture pressure relieving hole to form multiple cutting cracks; the roof rock layer is cut off along the cutting cracks of all the hydrofracture pressure relieving holes. By means of the method and the device, the influence of the advanced supporting pressure of the working face to the mining roadway can be effectively reduced, transferring of the prestress of the roof and weakening of surrounding rock can be achieved, the purpose of reducing and optimizing the mining stopping line position of the working face can be achieved, and the recycling rate of coal resources can be increased.