The invention provides a calibration technology for a vision sub-pixel of an embedded type machine with optical path adjustment, which is a calibration technology of an adjustable optical path with on-line vision measurement. Main technologies including an optical path adjusting technology, a sub-pixel angular point extraction technology and a sub-pixel vision calibration technology are adopted in a calibration process, wherein the optical path adjusting technology comprises an optical intensity saturation prevention technology and an objective surface parallel-adjustment technology; the sub-pixel angular point extraction technology utilizes a spatial moment; and the sub-pixel vision calibration technology is based on an ideal grid. The invention overcomes the defects of the traditional measurement technology, carries out high-precision and high-stability calibration on a camera on a production line and can automatically carry out the vision measurement by using the calibration technology on the production line and finally detect the quality qualification of products; in addition, by adopting a design algorithm based on engineering idea, the invention has the advantages of high precision and speed, low requirements for production environment quality and high instantaneity, can well meet the requirements of industrial production, and has important significance on the vision measurement of the products in actual industrial production.