In this paper, the tunneling properties of Bose-Einstein condensates containing one fermion impurity in an optical microcavity are investigated. Based on the Hamiltonian of the coupling system between the optical microcavity and the Bose-Fermi mixture in a double well, the analytical expression of ground-state energy level difference of particle tunneling and the occupation number difference are deduced. The results show that: the coupling strength between the optical cavity and the atom has an effect on the kind of preferentially tunneling particles and the ladder pattern of particle tunneling.