The thermal decomposition characteristic of benzoyl peroxide is a significant basis for guiding the safe application of benzoyl peroxide. The characteristic temperature and heat generation characteristics of the benzoyl peroxide thermal decomposition process were studied through multiple scan rate thermogravimetric analyses and density functional theory (DFT) calculations. The kinetic parameters of the benzoyl peroxide thermal decomposition reaction were calculated by using the isoconversional methods, and the most probable mechanism function of the benzoyl peroxide thermal decomposition reaction was explored via the Coats−Redfern method and the master-plots method. The results showed that the thermal decomposition reaction of benzoyl peroxide followed the reaction kinetics mechanism of random nucleation and nuclei growth, but it followed different models at the different reaction phases. Furthermore, the thermal decomposition of benzoyl peroxide is a complex process that may involve multiple parallel competitive reactions. The results benefit the safe application and loss prevention of benzoyl peroxide in industrial production.