A method to couple high power laser diode array (LDA) beams into a single multi-mode fiber which includs collimating, shaping, focusing and coupling is present based on the beam parameter product (BPP) of laser beam. The orthogonal surface equation of the collimating micro-lenses array is derived, the divergence angles after collimating and the parameters of the focused lens are calculated. As a example, a high power fiber coupled LDA module with the core diameter of 800 μm and numerical aperture of 0.37 is gotten and the coupling efficiency is more than 53%.