The reaction of difluorocarbene (CF2) radicals with OH is studied by ab initio molecular orbital theory. The potential energy surface of the reaction system is explored with density functional theory (B3LYP) and second-order Moller-Plesset perturbation theory (MP2). The quadratic configuration interaction [QCISD(T)] method is used to compute the energetics. The mechanism of the reaction is proposed for the first time. It is found that the major products of the reaction are CF2O and H atoms. The products can be produced through the CF2OH or CHF2O intermediates involved in the reaction. The suggestion of CF2O as a product of the CF2 + OH reaction is consistent with experiments.