Abstract：The settlement of high subgrade is common fault in highway engineering，it not only directly affects the quality and normal operation of highway，but also brings trouble to everyday maintenance. There are some treatments to deal with this problem. The method of the pressure grouting design，construction technique and quality control and test is introduced taking the treatment of high subgrade settlements in Guangyuan section of National Highway 108 for example. Furthermore，the relation between the economical performance and the grout ability of grouting liquid，the concretion rate and the road uplift，site contamination during grouting process are discussed. Finally，the reason for the settlement of the high subgrade in Guangyuan section of National Highway 108 is analyzed；and some advices for construction of the pressure grouting are presented.
