Abstract: Based on the achievements of psychology, philosophy, economics, and pedagogy, the paper takes the undergraduate education of Chinese university for an example, probing into the approximation measurement problem in labor complexity. It proves that the complexity of professional labor is determined by the complexity of professional study; while the complexity of professional study is determined by its cross disciplines and experience which is embodied in the main courses specified by experts. Hence the complexity approximation measurement system of the professional discipline and its corresponding professional labor complexity approximation measurement system are established.