University development planning, as a means of governance or organizational action, has two legitimacy sources:the preparation and implementation of the planning is based on external provisions or norms; the preparation and implementation of the planning obtains the understanding, recognition and support of internal organizations and groups. Its legalization mechanism is divided into that of strong meaning and that of weak meaning. The strong meaning legalization mechanism refers to the organizational systems and methods that effectively support planning and implementation; and the weak meaning means that the organizational systems are not complete enough, and the methods used are usually non-mandatory. In view of these two dimensions, the reform process of China's university development planning can be divided into three stages, namely, the establishment stage, the stage for the short-term disorder, and the transformation stage. The significance of strategic planning in the transformation stage lies in the fact that the road of transformation led by internal legitimacy has enabled colleges and universities to walk out of the dependent mode of development, establish a new mechanism of co-governance, and set the basis for the separation of supervision, management and evaluation. At the same time, it is also facing challenges such as "governing education through projects", how to construct the legalization mechanism, and whether the internal legitimacy is stable enough.