In this paper, polyphenylene sulfide（PPS） was synthesized through reactions of sodium sulfide and p-dichlorobenzene in N-methylpyrrolidone. Then antioxidant 4426, montmorillonite(MMT) were added into the PPS resin to improve its thermal oxidation stability. The polymer was characterized by FT-IR, Raman, and XRD analysis. Differential Scanning Calorimetry (DSC) was used to mensurate the oxidation induction temperature (dynamic OIT) of PPS, and Thermogravimetric analysis(TGA) was used to evaluate the thermal oxidation stability of PPS. The results showed that the addition of the antioxidant 4426, montmorillonite(MMT) leaded to a good improvement of the thermal oxidation stability of PPS. The PPS's dynamic OIT could up to 480.07°C and 481.61°C after mixed with MMT and anti-oxidant 4426, respectively. the sample of PPS mixed with both MMT and anti-oxidant 4426 has a dynamic OIT of 482.7°C.