Based on the singly occupied a-picture and the mechanism of charge fluctuation, the effective Hamiltonian of two-band Hubbard model is derived by using the degeneracy perturbation theory for the non-cuprate comoound Ｂａ1-xＫxＢｉＯ3. By considering the next neighbour pairing of two opposite spin holes in coordinate space, the Green's function equation of motion and superconductivity equation are obtained. Furthermore, how the superexchange interaction and the hopping energy affect the next neighbour pairing has been explained reasonably, and the superconductivity window is due to the Cooper pairing in coordinate space.