Epoxy resin DER 671X75 cured with hardener T31. Epoxy polymer composite materials DER 671X75/T31 were improved the mechanical properties, thermal stability by triphenyl phosphate (TPP) and nanosilica (fumed silica S5505). Triphenyl phosphate and nanosilica were dispersed in epoxy resin DER 671X75 by mechanical stirring and ultrasonic vibration. The structural morphology of materials was characterized by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The thermal stability and thermal properties of materials were characterized by Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The results showed that triphenyl phosphate with a content of 5 wt % in epoxy resin DER 671X75 improved the mechanical properties of epoxy polymer coating film DER 671X75/T31 with an impact strength increased 25%. The contents of 5 wt % triphenyl phosphate and 1 wt % nanosilica in epoxy resin DER 671X75 improved the impact strength of epoxy polymer coating film DER 671X75/T31 by 125%. The thermal stability of epoxy nanocomposite materials DER 671X75/5% triphenyl phosphate/1% nanosilica/T31 increased 45.35%. Epoxy coatings based on epoxy resin DER 671X75/5% triphenyl phosphate/1% nanosilica/pigments/fillers/additives/hardener T31 achieved mechanical properties, physical chemistry properties for coating and, had thermal degradation over 500 °C.