Atmospheric turbulence is one of the inevitable influence factor of resolution of optical imaging system. In order to research the effect of inner scale, outer scale, turbulent contour lines and height on resolution of optical imaging system, the optical resolution of optical imaging system considering inner and outer scale of slant atmospheric turbulence was derived, according to the optical imaging system integral resolution theory and modified Von Karman turbulence spectrum. ITU-R atmospheric turbulence structure constant model changing with height was used in numerical calculation. The results show that the effect of inner scale of turbulence on optical resolution is much less than that of outer scale of turbulence; the changes of inner scale will limit the effect of outer scale of turbulence on optical resolution; in slant transmission, turbulent contour lines has more influence than the effect of outer scale of turbulence; atmospheric structure constant near the ground will affect the optical resolution of optical imaging system mainly in the low height; the wind speed will be the major influence factor when the height beyond 5 000 m.