In this paper, a novel method called hydrothermally initiated dynamic extraction (HIDE) is proposed for the extraction of dimeric fullerene oxides such as C120O and C130O in the fullerene soot. In this method, the soot is hydrothermally treated prior to the extraction by organic solvent. As a result, a few types of dimeric fullerene oxides were efficiently extracted from the soot for the first time. The extraction efficiency was 40 times more than that of the Soxhlet extraction with organic solvents, and several dimeric fullerene oxides were obtained in milligram quantities. Furthermore, the analyses strongly indicated that the extract contains not only dimeric fullerene oxides but also higher fullerene oxides. The detailed purification procedures for each dimeric fullerene oxide are also presented in this report.