Abstract: Flame retardant low toxicity of phthalic nitrile composite was studied, by means of heat release rate, toxicity, harmful gas concentration, oxygen index, smoke optical density, horizontal burning, vertical burning. When irradiance was 50 kW/m², the heat release rate of the phthalic nitrile composite was 21 kW/m², ignition time was 500 s. Meanwhile, its oxygen index was greater than 70%, flame density was less than 20, show that phthalic nitrile composite is an ideal flame retardant low toxicity composite.