The work aims to achieve room-temperature curing of organic silicone resin and improve its high-temperature resistance and then prepare the room-temperature curing and high temperature resistant coating. The organic silicone resin with silicon hydroxyl as active functional group was used as the main resin, and the self-made polysilazane was adopted as the curing agent. Then heat-resistant pigments and fillers like SiC and glass powder were added to prepare a room-temperature curing and high temperature resistant organic silicone/ polysilazane coating. The curing process and heat-resistant property of resin were respectively characterized by infrared spectroscopy (IR) and thermo gravimetric analysis (TGA). Pencil hardness, and impact and high-temperature resistance were evaluated for the cured coatings added with fillers. The morphology of the coating after heat treatment was observed by metallographic microscope. The coating layer hardened into film after silicone resin and polysilazane mixed and reacted with each other for 72 h at room temperature. The N—H bending band in IR spectra disappeared and the intensity of absorption peak belonging to Si—N band decreased, so silicone resin and polysilazane reacted.. As the addition amount of polysilazane increased, thermal weight loss of samples decreased but residual weight added. When 32.5% cured samples of polysilazane were added, the weight loss at 400 ℃ was only 0.76% and the temperature for weight loss of 5% reached over 500 ℃. The adhesion of the cured coating was 0, and the toughness was level 1. After heat treatment, the surface roughness of the coating became better and the adhesion was significantly improved. Polysilazane can cure silicone resin at room temperature, improve the adhesion and increase heat resistance. The coating prepared by organic silicone resin cured by polysilazane has outstanding flexibility and high-temperature resistance for the maximum temperature over 400 ℃.