Abstract: Temporary anions, which are resonant particles, are formed when electrons are captured by molecules in the process of gas discharge. The study of microscopic parameters of resonance is helpful to reveal the microscopic mechanism of the macroscopic insulation strength of gas. Based on the orbital stabilization method, the influence of the diffuse function in Dunning's correlation consistency basis set on stabilization curves and the error of the long-range correction functional in calculating resonance energies are studied. Eventually, ωB97XD, LC-ωPBE and aug-cc-pVTZ+3p are used for analyzing the shape resonance parameters of CO₂, N₂, SF₆, c-C₄F₈, and i-C₃F₇C_N. The deviation between the calculated value and the experimental value of shape resonance energies of each gas is negligible. It is suggested that the lowest shape energy resonance is related to the insulation strength. The lower the energy of the lowest shape resonance is, the higher the insulation strength will be. The stabilization method is convenient to obtain the resonance parameters of gas molecules, which can be used to screen SF₆ alternative gases.