Multi-aperture receiving technology can effectively suppress intensity scintillation in wireless laser communication. However, the effect of the diameter, spacing and number of receiving aperture on improving the performance of wireless laser communication is not clear and complete. Therefore, an optical transmission method based on composite phase screen was proposed, and the characteristics of multi-aperture reception were studied. Firstly, the power spectrum inversion method was combined with Zernike tilt method to generate a composite phase screen, and the mathematical model of optical transmission multi-aperture reception was constructed. Then, the diameter, spacing and number of receiving aperture were changed to calculate the change of intensity scintillation at the receiving end. Finally, the variation of multi-aperture received intensity scintillation was analyzed under the actual optical transmission scenario with different atmospheric refractive index structure constants, wavelengths and transmission distances. The results show that the intensity scintillation of five receiving apertures with diameters of 0.2 m and aperture spacing of 0.4 m decreases from 0.2032 to 0.0524 when the structure constant of atmospheric refractive index decreases from 2.2313×10^?16 m^?2/3 to 1.5812×10^?17 m^?2/3. When the wavelength of light wave changes from 532 nm to 1550 nm, the intensity scintillation of five receiving apertures with diameters of 0.2 m and apertures spacing of 0.4 m decreases from 0.2165 to 0.1523. When the propagation distance increases from 7×10³ m to 7×10⁵ m, the intensity scintillation of five receiving apertures with diameters of 0.2 m and aperture spacing of 0.4 m increases from 0.0043 to 0.3239. This study summarizes the law of multi-aperture receiving characteristics of wireless laser communication.