In order to study the best technology of remediation of petroleum contaminated soil, naphthalene (NAP), a typical semi volatile organic compounds in petroleum contaminated soil was selected as the target pollutant, the simulated NAP contaminated soil was taken as the test soil, and the microwave(f=2.45 GHz) was used to restore the 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. A 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 best process parameters were obtained as follows: 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% under these conditions. The verification results show that the removal rate of NAP is 97.0%, which is only 0.31% different from the predicted results. The process parameters optimized by response surface methodology are reasonable and feasible, which may provide some reference for the industrial application of microwave remediation of soil.