The Baikouquan formation in the Mahu 1# well area is a typical tight oil reservoir with low porosity and permeability. Large-scale hydraulic fracturing in this well area faces three major problems，such as poor drag reduction effect of fracturing fluid， great damage to reservoir，scarce water resource and difficult treatment of oilfield sewage. Furthermore，the remaining oil distributes between fractures，and the recovery rate needs to be improved. In response to these problems，the drag reducer（JHFR） was prepared by dispersion polymerization using hydroxymethyl styrene，vinyl acetate，acrylamide，polyvinyl benzyl trimethyl ammonium chloride，etc. Then JHFR was compounded with the multifunctional additive（JHFD）to obtain a slick water fracturing fluid. The effects of fracturing water source and the clay mineral content of reservoir rock in target block on the hydration and swelling performance of clay in slick water were studied. And the damage of slick water to the Mahu tight oil reservoir was evaluated. The results showed that the dissolution time（15 s）of drag reducer JHFR was short，and direct mixing could be realized without mixing. The slick water composed of 0.1% JHFR and 0.2% JHFD had the characteristics of high drag reduction（76.9% drag reduction rate），low oil-water interfacial tension（0.89 mN/m），good anti-swelling effect（81.12% anti-swelling rate），etc. The system had good compatibility with the formation water and flowback fluid in the Mahu 1# well area，and had low damage to the core permeability. It was suitable for the large-scale continuous fracturing in this well area.