With a carbon fiber reinforced epoxy resin composite structure as an example, this paper studies the influence of the delamitation flaw on the compressive strength. The typical test pieces with preset delamitation flaws and the related test facilities were designed to test the compressive strength. The effects of the location and the size of the delamitation flaw are studied by numerical simulations combined with experiments. It is shown that the position of the delamitation flaw affects the delamitation form of the laminate and the small scale delamitation flaws do not affect the compressive strength. This conclusion is useful for the design and manufacture of the aircraft structures.