High salt-tolerance inverse emulsion resistance reducing agent applicable to shale reservoir fracturing transformation

The invention discloses a high salt-tolerance inverse emulsion resistance reducing agent applicable to shale reservoir fracturing transformation. The high salt-tolerance inverse emulsion resistance reducing agent is prepared from the following raw materials in percentage by weight: 30% to 45% of non-ionic monomers, 5% to 15% of cationic monomers, 12% to 20% of a non-polar solvent, 0.5% to 5% of an emulgator, 0.001% to 0.1% of an initiator, 5% to 10% of a phase inversion agent and the balance of water. Functional monomers are added in a molecular chain, and the structure stability of the resistance reducing agent under the condition of high salinity water quality is improved, so that the resistance reducing agent still has good resistance reduction performance under the condition of 100 thousand ppm high salinity water quality, the resistance reduction rate can reach 75.8%, and the resistance reducing agent is applicable to repeated recycle of a flowback fluid in shale reservoir fracturing transformation; and