The invention relates to a strong-inhibition drilling fluid system, comprising the following components by mass percent of 2.5-4.5% of bentonite slurry, 0.1-0.3% of alkaline regulator, 0.3-2.0% of shale inhibitor, 0.2-0.4% of metal ion polymer, 2.0-5.0% of walchowite, 2.0-5.0% of sulfomethal phenolaldehy resin, 1.0-3.0% of cation emulsified asphalt, 0.5-3.0% of lubricating agent, 0.2-0.8% of emulsifier, 2.0-8.0% of crude oil, and 1.0-3.0% of calcium carbonate superfine powder according to 100% of water. The compound in a general formula (I) is also provided; R1 is H or CH3; R2 is H, CH3 or C2H5; and X is an integer between 2 and 20 and applied to the shale inhibitor. The compound and the cation emulsified asphalt are applied to the drilling liquid system; the drilling liquid system is strong in shale inhibition; the shale recovery rate can be up to 90.33% and is improved by over 35.02% in comparison with that of water shale; the high temperature resistance can be up to 150 DEG C; the lubricating friction coefficients before and after aging respectively are smaller than 0.1; the strong-inhibition drilling fluid system is strong in capacity of resisting poor soil, salt and calcium contamination, strong in rejection capability, and good in blocking effect; the API (American petroleum institute) water loss of the drilling fluid is smaller than 4.5mL, and the HTHP (high temperature and high pressure) water loss is smaller than 12mL.