Abstract: In view of the problems existing in the consolidation grouting of the ultra-high arch dam of Wudongde Hydropower Station, the relaxation characteristics of dam foundation excavation are analyzed. Through indoor material tests and field process tests, the materials and processes for sealing the cracks in bare rock are developed, which solves the problems of low pressure and poor effect of the consolidation grouting without cover weight, and puts forward the method of "surface sealing, shallow densification, deep pressure rise, less lead pipe" for the whole dam without cover weight consolidation grouting, which not only ensures the quality of the consolidation grouting of the dam foundation, Moreover, it does not occupy the concrete warehouse surface, and solves the problem of the interference between the covered consolidation grouting and the concrete pouring construction. It has been successfully applied in the consolidation grouting of the dam foundation of the ultra-high arch dam of Wudongde Hydropower Station, which can be used as a reference for similar projects.