In order to study the best technology of microwave remediation of petroleum contaminated soil, the typical semi volatile organic compounds Naphthalene (Nap) in petroleum contaminated soil was selected as the target pollutant, and the simulated Nap contaminated soil was taken as the test soil. On the basis of single factor experiment, the Box-Behnken experiment design of response surface method was adopted, and the removal rate of Nap was taken as the response value. The quadratic multiple regression model was established with microwave power, irradiation time, soil thickness and soil moisture content as the influencing factors. The ANOVA model reached a very significant level, in which the microwave power had the most significant effect. The results showed that the wave power was 768 W, the irradiation time was 19 min, the soil thickness was 3.2 cm, the water content was 16 %, and the removal rate of Nap was 97.3%. The results showed that the removal rate of Nap was 97.0%, which was only 0.31% different from the predicted results. The results showed that the process parameters optimized by response surface methodology were reasonable and feasible.