Based on the requirement of the synthesized polymer resistant to higher temperature and lower cost demand of water-based drilling fluid system, a novel polymer, which named poly(AMPS/AM/SSS), was synthesized using acrylamide (AM), 2-acrylamido-2methylpropanesulfonic acid (AMPS), and p-styrenesulfonate (SSS). At first, the molecular structure was investigated through Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance hydrogen spectroscopy ( 1 H-NMR) and element analysis. Simultaneously, the molecular weight and distribution was obtained by gel chromatography method. Moreover, the thermal stability was produced by thermal analysis (TG). Secondly, the poly(AMPS/AM/SSS) was introduced into water-based drilling fluid system. As a result, it was shown that the use of poly(AMPS/AM/SSS) significantly improved the filtration performance of drilling fluid system. When the adding amount is 1.2 wt %, the FL API of drilling fluid system is 9.20 mL. Moreover, it was found that the flow curve of water-based drilling fluid systems are more fitted to the Herschel-Bulkley flow model. Besides, the temperature resistance of water-based drilling fluid system was obviously improved. Furthermore, it was confirmed that the cost of water-based drilling fluid system was significantly reduced. During this study, the filtration mechanism of the synthesized poly(AMPS/AM/SSS) was studied by adsorption analysis, Zeta potential method, and morphology analysis.