Oil and gas exploration and development in deep and ultra-deep well have put forward higher requirements on the temperature resistance of fluid loss reducer for drilling fluid. Taking advantage of β-cyclodextrin’s special rigid stabilizing structure in the shape of a conical ring table and special adsorption ability of inner hydrophobicity and outer hydrophilicity，β-cyclodextrin （β-CD） was grafted by maleic anhydride （MAH）. Meanwhile，3-（trimethoxymethylsilyl） propyl methacrylate （KH₅₇₀） with excellent high-temperature stability was introduced，and then copolymerized in an aqueous solution with p-styrenesulfonic acid sodium salt（SSS）and dimethyldiallylammonium chloride（DMDAAC）. As a result，a high-temperature resistance fluid loss reducer（LY-1）was synthesized. The optimum preparation conditions of LY-1 were determined by measuring the high-temperature and high-pressure filtration loss of sodium bentonite based slurry containing 3% LY-1. The structure of LY-1 was characterized by gel chromatography，infrared spectrometry and thermogravimetric analysis. The effects of LY-1 on the filtration loss and rheological properties of base slurry were evaluated. The performance of LY-1 was compared with that of three commonly used high temperature resistance fluid loss reducers. The results showed that the optimum synthesis conditions of LY-1 were obtained as follows：25% total mass fraction of the monomer，1% initiator mass fraction of the monomer mass，15∶3∶2∶15 mass ratio of the monomers（SSS，KH570，DMDAAC and MAH-β-CD），10 pH value，75 ℃ reaction temperature，and 4 h reaction time. The average relative molecular mass of LY-1 was 14 589. The total heat loss mass was about 35.98% at 284—453 ℃，which meant it had good temperature resistance at 300 ℃. LY-1 had a good performance of lowering the filtration loss at high temperatures. When 3% LY-1 was added to the base slurry，the filtration loss of base fluid was reduced from 143 mL to 12 mL after hot rolling at 200 ℃for 16 h，with a reduction rate of 91.6%. The effect of LY-1 on the rheological properties of base slurry was small. It’s filtration reduction performance and temperature resistance were better than those of three commonly used high temperature resistance fluid loss reducers.