It was pointed out that the ordered aero optical aberrations in Hydrogen Fluoride (HF) continuous wave chemical laser (CWCL)′s cavity is one of the main factors influncing laser beam quality by the analysis of the inhomogeneous medium in laser cavity. The 2D refractive index model in HF CWCL was set up to simulate the inhomogeneity distributions in main tone/over tone HF CWCL′s cavities in the condition of power/zero power output. With it, the performance and beam quality in 3 Slot (3S) and 2 Slot (2S) structure lasers were computed and analyzed. By the simulation, it was shown that the ordered aero optical aberrations in the telescopic unstable cavity are not significant in nozzles array of 1 m length. But with the increase of the length of nozzles array, it will be important, especially for the over tone HF lasers. In addition, the performance and beam quality of 3S are better than that of 2S.