The invention provides a method for detecting defects of a contact hole manufacturing process. A test structure is manufactured by the same contact hole manufacturing process in the prior art; and shared contact holes in a PMOS structure in the test structure are adjacent to shared contact holes in an adjacent NMOS structure, so that two columns of shared contact holes which are in equal potential originally form unequal potentials. Metals are deposited in all contact holes to form metal bolts; and electron beam scanning is finally carried out on the structure, thereby observing the brightness condition of each contact hole under a scanning electron microscope.