In order to assess the relation between spraying techniques and depth of penetration by PS solutions therefore providing a basis for comparing the efficacy of the processes. The Hezhoubu site of Dunhuang country in Gansu province was chosen as a test site. At the selected region, objects at this site were sprayed at different times with 3%, 5% and 7% PS solutions, and the depth of penetration was measured. The test data indicts: (1) spraying three times with 7% PS can satisfy anti - weathering requirements by delivering a moderate PS dosage to the inner wall; (2) spraying three times with S % PS can satisfy anti - weathering requirements by delivering a PS dosage to the outer wall. These results show that spraying several times can will achieve a satisfactory consolidation, and that it is best to use a high - concentration PS solution for permeable low - density soils and low - concentration PS solution with permeable high - density soils. These results provide a basis for considering their use for anti-weathering consolidation of earthen architecture in the Jiaohe ruins.