Based on the generalized Huygens-Fresnel diffraction integral formula, analytical expressions of coherent superposition multiple laser beams projection light focal spots intensity in hohlraum and wall of indirectdriven fusion device is calculated. The effect of the axial distance, defocus amount, incident angle and focusing F number on cavity internal glazing cross-section light spots intensity distribution and the effect defocus amount, incident angle, focusing F number and diameter on hohlraum wall light spots intensity distribution is analyzed. Simulation results show that within a fixed range, the interference becomes less obvious, and the intensity distribution becomes more uniform with the increasement of defocus amount and F number. In addition, the obtainment of better uniformity of light spots in hohlraum wall is relevant to hohlraum diameter and incident angle.