The invention provides fireproof filler based on molybdenum waste and a fireproof coating. The fireproof coating comprises a film-forming agent, a carbonizing agent, a catalytic dehydration agent and a foaming agent and further comprises the fireproof filler based on molybdenum waste. According to the fireproof filler based on the molybdenum waste, sol is formed with molybdenum waste as a main material and chloroplatinic acid, scandium chloride hexahydrate, anhydrous isobutanol and diethanol amine as auxiliary materials, precursor sol is obtained after evaporation condensation, the precursor sol is dried at high temperature and ground, and the fireproof filler is prepared. The fire-retarding and corrosion-resistant fireproof coating which can effectively solve the problem of release of harmful gas in the heating process is provided to overcome defects about fireproof and corrosion-resistant effects and release of toxic and harmful gas decomposed during heating in the fire prevention process. With the adoption of the fireproof filler and the fireproof coating, environmental pollution can be reduced, and secondary recycling of the molybdenum waste can be realized.