Dredging type fracturing method for high-rank coal reservoir

The invention provides a dredging type fracturing method for a high-rank coal reservoir. The dredging type fracturing method comprises the steps that the depth range of primary coal in the high-rank coal reservoir is determined according to logging data; perforation is conducted in a middle area, corresponding to the depth range where the primary coal of the high-rank coal reservoir is located, in a shaft, and a plurality of holes are formed in the inner wall of the shaft; first fracturing fluid is injected through the plurality of holes, and a first crack is formed in the primary coal of the high-rank coal reservoir; second fracturing fluid is injected through the plurality of holes, a second crack is formed in the primary coal of the high-rank coal reservoir, the first crack communicates with the second crack, and the second fracturing fluid is mixed liquid of the first fracturing fluid and a crack propping agent; displacing fluid is injected from the shaft, and the first fracturing fluid and the second fra