The hole stress concentration of composite plate is studied by FE method for designing the composite mechanical connections. The relations between the stress concentration and the d/B、H/d is concluded in the paper: (1) The relative width d/B and relative edge distance H/d have a great effect of stress concentration. (2) The maximum circumferential concentration factor decreases with the increase of H/d, but ratio of maximum radial stresses to bearing stress almost has no change. (3) The ratio of maximum circumferential stress to bearing stress increase with the decrease of B. As d/B changes, the Krd almost has no change, but the radial stress changed visibly. These results can be referred to design composite mechanical joint.