The impact of magnetohydrodynamics (MHD) turbulence of the solar flare plasma atmosphere on the thermal X-ray flux propagation in 1−10 keV energy range has been examined. As the MHD turbulence consists density, velocity and magnetic field fluctuations, we specifically examined how the fluctuations in the density field over the inertial sub-range affect the index of refraction of the atmosphere. The fluctuations in the index of refraction lead to variations in the properties of X-ray flux of 1 − 10 keV energy passing through it – a phe nomenon known as optical turbulence. We measured and analysed parameters of optical turbulence and spatial coherence by using the structure and second order mutual coherence functions. The mean values obtained were: index of refraction ≈ 1.309885 × 10 −4 , index of refraction structure constant ≈ 1.70856 × 10 −13 m −2/3 , Kolmogorov power density spectrum ≈ 7.38468 × 10 11 J m −3 , spatial coherence radius ≈ 8.76129 × 10 −12 m, and spatial coherence ≈ 5.75347 17 × 10 −24 m 2. We observed that the spatial coherence parameters decreased as the turbulence strength increased over the inertial sub-range length scale of the turbulence. This indicates that the density fluctuations significantly affect the spatial coherence properties of the thermal X-ray flux passing through it. Our findings exhibit the presence of strong optical turbulence covering the entire loop half-length of the solar flare. The analysis of the results show a compressible, density fluctuations and dispersive nature of the X-ray flux over the inertial sub-range scale in the solar flare turbulence. The density fluctuation is found associated with the non-linear cascade of the turbulent energy, compressible, fast and slow modes of the MHD turbulence.