(1) Adding a special catalyst into the waste oil raw material, and carrying out catalytic cracking at medium temperature, the waste oil and various mineral oil products can achieve the cracking effect: (2) the gas components obtained after cracking are further catalytically cracked in a fixed bed to obtain oil and gas; (3) Fractionating oil and gas, respectively collecting gasoline and diesel fractions; (4) The gasoline and diesel fractions are refined separately. Through the impurity removal device, the whole process not only ensures the product quality, but also has simple equipment investment, reduced volume, simplified process and shortened production cycle. The obtained oil has good quality, high transparency and low carbon content, which can reach the national standard of No.93 gasoline. The yield is high, and the total oil obtained accounts for more than 90% of the weight of waste engine oil.