In this study, the purpose of evaluating the site applicability of the chemical oxidation method using hydrogen peroxide among the in-situ cleanup techniques was to be applied to areas where excavation is restricted due to ground structures and underground burials. The range contaminated with TPH was 951 m3 and the TPH peak pollution concentration was 10,988 mg/kg, and based on the determination of hydrogen peroxide demand, the Cetane of 1 kg was calculated as 7.37 kg H2O2 and 2.27 kg H2O2 for organic matter in soil. The concentration of hydrogen peroxide was 35% and the input was 88 tons. The concentration was reduced from N.D. to 140.21 mg/kg as a result of site application in contaminated areas, and the reduction rate was 96.2 to 99.8%. The on-site applicability assessment using hydrogen peroxide confirmed that high-concentration contaminated areas can be reduced with high efficiency. In addition, when examining the amount of injection of an oxidizer to reduce time and cost in cleaning up contaminated soil using hydrogen peroxide, it was confirmed that the higher the concentration of hydrogen peroxide, the higher the efficiency of reducing it, the higher the efficiency of the penton oxidation when the presence of iron in the soil, or the addition of a catalyst iron salt. In addition, although the optimal concentration of hydrogen peroxide was found to be 10%, it is deemed necessary to consider other factors that may affect the efficiency of reducing pollution as a result of indoor experiments, and to calculate the appropriate concentration through field demonstration tests, and to determine whether catalyst is added.