The invention discloses a method for detecting the
diameter of an outer wall of a tapered case of an
aviation engine on line. According to the method, a five-coordinate
numerical control milling center with a Renishaw MP10 trigger-type measuring head is equipped, tapered case parts and a mounting seat on the surface of a tapered case are equipped; a fine adjustment ring gauge of the used measuring head is measured on line; a
point contact-type measurement mode is adopted; a
machine tool siemens
control system Sinumeric 840 D on-line measurement technology is adopted; and an on-line measurement quick
tool path amendment and error compensation generation technology is adopted. The method has a broad application prospect; and by the on-line measurement technology, a numerically-controlled
machine tool is impelled to form a
machining and detecting integrated
numerical control machining unit. By the method, the traditional manufacturing mode that a design characteristic is equipped with a set of measurement tool in the current industry is changed, the manufacturing cost of the tool is saved, repair labor-hour is saved, and first-pass yield of
product processing is improved, so that the
development period and the production cost of new products are reduced.