Slickwater plays a crucial role in volumetric fracturing of shale gas reservoirs，and anionic polyacrylamide“water-in-oil” emulsion has been normally used as the drag reducer for slickwater. However，poor tolerance to inorganic salt，incompatibility with cationic clay stabilizers were evidenced in practical uses. To address these issues，a series of ampholytic polymers SCJZ were prepared by inverse emulsion copolymerization，and their solubility，drag reduction efficiency and compatibility with cationic clay stabilizers were examined. Then a slickwater system based on the ampholytic polymer drag reducer SCJZ-2 was developed，and its properties were tested prior to field applications. It was found the viscosity-average molecular weight of the polymer SCJZ-2 prepared with AM，AA，AMPS and DMDAAC mass ratio of 70∶20∶5∶5 was higher than 12 million，and the dissolution time of the polymer was less than 3 min，and SCJZ-2 could play a role in drag reduction within 30 s，which ensured the online continuous mixing of slickwater fracturing fluids. SCJZ-2 showed good compatibility with three commonly-used clay stabilizer，improved drag reduction behavior in both fresh water and synthetic formation brine，and the friction loss was around 75% at 10 m/s pumping rate. The slickwater systems prepared from either fresh water or synthetic formation brine with formulation of 0.1% SCJZ-2，0.1% choline chloride and 0.2% alkyl polyglucoside could satisfy the basic criteria of surface tension lower than 28 mN/m，volume expansion less than 3 mL and drag reduction higher than 70%，and good feedback from hydrofracking in shale gas reservoirs was attained.