Abstract: Higher education has entered the stage of connotation development with quality improvement as the core. How to do a good job in the construction of internal quality assurance system of higher vocational colleges under the background of “Separation of Management, Running and Evaluation” is the fundamental of teaching quality. Taking the opportunity of “National High Quality Water Conservancy Higher Vocational College Construction”, Shanxi Conservancy Technical Institute has perfected its internal quality assurance system, implemented the teaching diagnosis and improvement system with teaching supervision and teaching evaluation as the starting point and informatization platform as the carrier. It has carried out exploration and practice from five aspects. In order to lay a foundation for the implementation of the fundamental task of cultivating people by virtue and improving the quality of talent cultivation. it has formed the “Two-wheel Drive” internal quality assurance system construction mode of teaching supervision and teaching evaluation.