Based on the high loess-filled project in Yan'an new district, a series of moistening deformation tests with different initial compaction degrees and initial water contents in high pressure are carried out for compacted Q₂ loess to study how the coefficient of moistening deformation change with the increasing of the vertical pressure, and the main factors influencing the moistening deformation characteristics. The results show that the-p curve greatly is different from different initial compaction degrees and initial moisture contents; Compaction degree and moisture content have a great influence on the moistening deformation characteristics of compacted Q₂ loess, the amount of moistening deformation saturated can decrease greatly by increasing them. Moreover, compacted Q₂ loess will lose collapsibility when its compaction degree is higher than 90% or moisture content is higher than 16.8%.