The invention discloses a hydration induction pretreatment and judgment method before fracturing of a shale reservoir. The hydration induction pretreatment and judgment method comprises the followingsteps that (1), a cable or a coiled pipe is adopted to conduct perforation operation on a first section of the reservoir; (2) the cable or the coiled pipe is taken out; (3) the displacement is slowlyincreased so as to pump clean water into a well shaft to conduct trial extruding, and the maximum displacement does not exceed 5m3/min; (4) the clean water is pumped in the well shaft continuously; (5) after the clean water is pumped, a well is closed to wait for generation of a hydration reaction, and the hydration time is determined to be 10-18 hours through an indoor core hydration experiment;and (6) judgment is conducted on the in-site effect of pretreatment. According to the hydration induction pretreatment and judgment method, pretreatment is conducted on the shale reservoir before construction of main fracturing, thus the complexness of the fracture network of reservoir fracturing can be further improved, the seepage channels of reservoir fluid are increased, the seepage resistanceof the liquid is reduced, and achievement of yield maximization of a single well is facilitated. The method is high in in-site operability, and low in operation cost.