The invention discloses a blind hole inspection method for multi-layer HDI printed circuit boards. The method includes the following steps: designing leakproof devices as a standardized template, andsetting an exposure film; directly or horizontally putting the leakproof devices nearby the four corners and a molding wire of an HDI printed circuit board, four groups being on the front side and four groups being on the back side, the total being eight groups, wherein the leakage devices are more than 100 mil from the outer board cutting edge of the HDI printed circuit board; and lasing blind holes on a laser station by computer-assisted manufacturing, using an image controller to inspect the leakproof devices, installing a buzzer on a quality control station, and detecting blind quality ofthe HDI printed circuit board according to signals of the buzzer. The preparation method of the invention can effectively monitor hole deviation and hole leakage status of blind holes of all layers, and so an operator can timely carry out adjustment when the production of the multi-layer HDI printed circuit boards is abnormal to avoid the failure of subsequent processes.