Abstract: AlBO_W whisker Al matrix composites were fabricated by squeeze casting technique. First, according to the basic principle of fluid dynamics in porous media and Laplace equation, the squeeze casting infiltration process of metal melt fluid in the porous whisker preform was analyzed. The paper indicated that metal melt fluids infiltrated the whisker preform by a disordered fluid status. And then, the effect of the length of whisker on the void structure of the porous preform was analyzed in detail.