Based on the generalized Huygens-Fresnel principle, the quadratic approximation and integral transformation techniques of the Rytov phase structure function are used to derive the expression of the turbulence distance and the M2 -factor of array Gaussian-Schell mode beam propagating through oceanic turbulence. The simulation methods of beam superposition are cross-spectral density function superposition and intensity superposition. The simulation results show that the turbulence distance and M2 -factor of the linear array Gaussian-Schell mode beam in oceanic turbulence are related to the coherence length, the number of array beam and the separation distance. The turbulence distance and the M2 -factor for superimposition of the cross-spectral density function are always smaller than for the superposition of intensity. For superimposition of the cross-spectral density function, when the propagation distance is less than 30 m and beam number is 3, the M2 -factor is the smallest curve. Also, the propagation distance is less than 700 m and beam number is 1, the M2 -factor is the minimum curve. When the propagating distance is more than 700 m and beam number is 3, the M2 -factor is the minimum curve. The optimization of beam parameters and superposition methods can obtain the better beam quality.