Water-base fracturing fluid with low harm to permeability of reservoir bed and diversion capability of crack

The present invention relates to an improvement on oil-field water base fracture fluid formula. Said water base fracture liquid is composed of base fluid and cross-linking liquor according to a certain ratio. Said base fluid is formed from (by wt%) 0.25-0.40% of thickness agent, 0.15-0.30% of cleanup additive, 0.10-0.20% of emulsion-breaking emulsion preventer, 1.0-2.0% of antiswelling agent, 0.10-0.20% of clay stabilizing agent, 0.1-0.15% of vegetable gun stabilizing agent and 96.65-98.3% of water, and the cross-linking liquor is formed from 3.0-6.0% of cross-linking agent, 0.4-1.2% of breaking agent and 92.8-96.6% of water, and the volume ratio of base fluid and cross-linking liquor is 20-50:1. Said invention can effectively improve fracture fluid properties, and its damage to reservoir permeability and fracture conductivity can be minimum.