We propose a new mechanism toward the solution to the doublet-triplet Higgs mass splitting problem in the supersymmetric grand unified theory. Our model is based on the gauge group SU(5)⌄H × SU(5)⌄GUT, where SU(5)⌄H and SU(5)⌄GUT are a new strong gauge interaction and the ordinary grand unified gauge group, respectively. The doublet-triplet Higgs mass splitting is realized through the quantum deformation of moduli space caused by the strong SU(5)⌄H gauge dynamics. The low energy description of our model is given by the minimal supersymmetric standard model.