In view of the complexity of underwater laser transmission channel caused by oceanic suspended particles, the effect of oceanic suspended particles on the underwater optical communication link is studied based on equivalent spherical particle Mie scattering theory and Monte Carlo simulation method. The characteristics of suspended particles and the relationship between the incident wavelength and the optical coefficients are analyzed. The effects of particle size and complex refractive index on the received normalized energy, received light intensity, channel transmission length and channel delay are investigated. Theoretical analysis and simulation results indicate that optical coefficients of the particles increase with the increase of particle size, thus the received normalized energy under same channel length decreases, received light intensity decreases, and the channel time delay increases. The smaller the imaginary part of the complex refractive index of the particles is, the stronger the received normalized energy and the greater the peak intensity of the received light are. However, when the imaginary part of the complex refractive index is the same but the real part is different, the magnitude of the received intensity peak depends on the albedo. The larger the albedo is, the stronger the received intensity is.