Porous parallel-connected grouting method and device for reinforcing roadway weak surrounding rock

The invention provides a porous parallel-connected grouting method and a device for reinforcing a roadway weak surrounding rock. Hole sites of grouting hole are arranged in a plum flower shape, and an electric grouting pump with a large flow (no less than 52L/min) and a grouting pipe with a large diameter are adopted to be connected with 3-9 grouting pipelines through a multi-level shunt controller; a pressure gauge, a control valve and a flowmeter are all installed on each grouting pipeline so as to be used for controlling the pressure and the flow of the grouting holes in real time; the same position with similar development degree of damage and a crack on a bottom plate, a side part or a top plate in a certain region of a roadway is selected to punch with a plurality of grouting holes,and grouting anchors are installed; and a plurality of grouting anchors are connected through a plurality of grouting pipelines so as to realize simultaneously grouting on the plurality of grouting holes. When slurry in one hole does not flow any longer, and the grouting pressure achieves above 2MPa, grouting of the grouting hole is stopped, the grouting pipeline is connected to the next groutinganchor so as to implement grouting of the next grouting hole until the grouting holes in the region are all grouted. The grouting speed is enhanced by above 3-9 times, thereby greatly enhancing the self bearing ability of the surrounding rock.