PEPA-EG/EP composite coatings were prepared by adding pentaerythritol phosphate (PEPA) and ex-pandable graphite (EG) as composite fillers to waterborne epoxy resin (EP). The effects of composite fillers with different mass ratios on the flame retardancy and corrosion resistance of PEPA-EG/EP com-posite coatings were investigated by fire resistance limit analysis, thermogravimetric analysis, limiting oxygen index test, vertical burning test, residual carbon scanning electron microscopy analysis, residual carbon infrared analysis, electrochemical impedance spectroscopy testing and adhesion experiments. The results show that when the mass ratio of composite filler to waterborne epoxy resin is 15:100, composite coating has the best flame retardant properties and corrosion resistance. The time when the back temper-ature of the steel sheet reaches 500℃ is 38 min，the limiting oxygen index reaches 27.2%，the vertical combustion performance exhibits V-1 level，the residual carbon amount increases from 0.55% to 27.79% at 800℃，and EP2 has the highest impedance value during electrochemical impedance spectroscopy testing af ter 480 hours of immersing.