Transition is the basic phenomena of complex flow regime changes in fluid mechanics. So far, the axiomatic expression and rigorous mathematical description of transition and separation are important basic scientific problems, which are also of great significance to the development of Applied Science. This article obtaining the basic conditions and general conditions for transition through the excited state theory of flowfield, which is derivation based on the N-S equations, combined with Euler’s description point of view, applied tensor analysis and with the help of the basic principles of superposition states of quantum mechanics. The research of this paper provide a theoretical view for the study of turbulence mechanism.