Abstract: Tapping is a common processing feature in machining, and it can be used in two ways of machine tapping or manual tapping according to the processing working conditions. The manual tapping is very important to maintain the verticality of the tap for the tap can not maintain the verticality of tapping and can not be measured by angle ruler when machining the blank hole, arc face, interference hole, etc. Aiming at the problem of maintaining and measuring the verticality of manual tapping, three design schemes of maintaining verticality by manual tapping are provided in this paper, and the processing performance and operation flow of the three schemes are compared. The position of the tap must be carefully checked and corrected by manual tapping to ensure that the tap is perpendicular to the thread base of the workpiece. Then it verifies that the three schemes can be implemented in actual processing. It provides reference for the processing of manual tapping to maintain the verticality.