According to the typical loess in Shuozhou in Shanxi province, tests involved in compaction characteristics, shearing strength characteristics and disintegration are carried out by using loess and three kinds of improved loess, namely lime and fly-ash, lime and cement, cement and fly-ash. The best improved soil method is selected. The test results indicate that the compact hybrid structure is formed by fly ash and loess. The activity of fly ash is activated as a result of the lime mixing. A series of hydration reaction prompt the intensity of modified loess. And the physical and mechanical properties of improved loess are improved noticeably.