3 kinds of laminate samples reinforced by UD, 0/45/-45, 0/45/90/-45 multi-axial fabric respectively, were manufactured by the vacuum infusion moulding process. Each laminate had 4 types of thickness. Experiment was made to investigate the short-beam shear strength and the failure mode of them. The finite element model of the short-beam shear sample was established, and the interlaminar shear stresses in different positions were calculated. The result shows that the free edge delamination failure is liable to occur with the increment of the off-axis plies which is mainly due to the stress gradient through the width direction. The interlaminar shear strength of the 0/45/-45 laminate is the highest of the 3 kinds of laminate with the same thickness. There are size effects in the short-beam shear strength test, the shear strength decreases while the sample coefficient of variation increases with the thickening of laminate.