Polyester fiber materials and its products have developed rapidly, constantly replacing traditional materials such as cotton and metal, and are widely used in various fields of daily life and social production. However, there are some safety problems that cannot be ignored in polyester fiber and its products: firstly, it is flammable and the flame spreads quickly; Secondly, the high temperature droplets that cause secondary damage; Thirdly, when burning, it will produce a lot of heat, smoke and toxic gases. It does great harm to people, environment and social production. Therefore, it is necessary to develop a flame retardant system with good flame retardant effect, droplet resistance and low smoke to modify polyester materials. In this paper, silicon dioxide is used as a new flame retardant additive to modify the flame retardant belt. Secondly, the flame retardant tape was modified by a smoke suppression system composed of zinc borate, ferrocene, zinc oxide and molybdenum trioxide. Then, the intumescent flame retardant system composed of ammonium polyphosphate, pentaerythritol and melamine and the smoke suppression system composed of zinc oxide, ferrocene, magnesium oxide and zinc borate were used to modify the flame retardant belt. The combustion performance of the sample was tested by limiting oxygen index instrument and vertical combustion instrument. The results show that the oxygen index of the modified flame retardant is as high as 29.0%, and it has droplet resistance. The thermal properties of the samples were tested by thermogravimetric analysis and differential scanning calorimetry. The results show that modified silica, zinc borate and intumescent flame retardant system all change the thermal decomposition process of plasticized board, and the residual carbon content of the system increases to 30.0%. The results of smoke density test show that adding smoke suppressant can reduce the smoke output, and the maximum smoke density (Dm) of the flame retardant belt modified by the expansion flame retardant and smoke suppression system can be reduced by 40%. In this paper, the polyester fabric was treated with a system composed of hydroxyethyl diphosphonic acid and sulfamic acid, and the polyester fabric was treated with a new expansion system composed of hydroxyethyl diphosphonic acid, ammonium sulfamate and pentaerythritol. The combustion performance of the sample was tested by limiting oxygen index instrument and vertical combustion instrument. The results show that the oxygen index of the flame-retardant polyester fabric is as high as 28.0%, the vertical combustion time is shortened to 0.05 seconds, and it has droplet resistance. The thermal properties of the samples were tested by thermogravimetric analysis and differential scanning calorimetry. The results show that the initial decomposition temperature of polyester after flame retardant finishing is advanced, the thermal decomposition temperature is widened, the exothermic peak is weakened and the char formation is increased. The microstructure of combustion residue was obtained by scanning electron microscope. The photos show that after flame retardant finishing, a porous expanded carbon layer is formed after combustion.