The effect of bitumen ozone-oxygen mixture pretreatment followed by cracking on thermolysis processes was investigated. Pretreatment of natural bitumen allowed to intensify the process of destruction of high-molecular components of raw materials, the content of which decreased by 8–15% wt. In the resulting liquid cracking products, oils predominate from 70 to 80% wt. Based on the formalized model of the thermal transformation of high-molecular components of the raw material, the rate constants of the bitumen thermolysis reactions (k) and the effect of pretreatment of the ozoneoxygen bitumen mixture on the cracking reactions are calculated