The invention discloses a slippery water fracturing fluid with ultra-low interfacial tension with crude oil after degradation. The slippery water fracturing fluid is prepared from an ultra-low interfacial tension drag reducer, a demulsify-cleanup additive, a clay stabilizer and a degrading agent. A preparation method of the slippery water fracturing fluid comprises steps as follows: 0.02%-0.10% in percentage by mass of the ultra-low interfacial tension drag reducer, 0.1%-0.2% in percentage by mass of the demulsify-cleanup additive and 0.3% in percentage by mass of the clay stabilizer are added to every ton of water, the agents are mixed to form a homogeneous solution, and 0.08% of the degradation agent is added from a mixing tank of blending equipment during construction. Additives of the slippery water fracturing fluid are all liquid phase, and the slippery water fracturing fluid can be quickly dispersed in water, have good salt tolerance, are not easily affected by the content of bacteria in a fluid preparation solution and have a stable drag reduction effect under the construction displacement of 6-20 m<3>/min; when applied to improvement of low-permeability oil and gas reservoirs, the slippery water fracturing fluid can reduce the interfacial tension between a gel breaking liquid and crude oil and reduce string and construction friction, helps production of the crude oil, increases of the yield of the crude oil and can be prepared repeatedly from backflow fracturing fluids.