Light intensity and scintillation index changes of the Laguerre-Gaussian (LG) vortex beam propagated in ocean mixed-media are investigated by numerical simulation based on the random media phase screen method. Simulation results show that the spot size of the LG vortex beam will gradually grow as propagation distance increases, and the dark spot area on the central axis of the beam will gradually shrink until it disappears entirely. When the propagation distance increases from 30 m to 100 m, the scintillation index will quickly increase and then gradually stablize, but when the propagation distance is over 100 m, the scintillation index will decrease. The scintillation index will increase with the increase of the propagation distance for LG vortex beams with different wavelengths, regardless of the wavelength value, and the shorter the wavelength, the larger the scintillation index. The greater the mean square temperature dissipation rate, or the greater the temperature-salinity ratio, or the smaller the kinetic energy dissipation rate, the stronger the ocean turbulence, and the larger the scintillation index.