In order to study the effects of different straw application depths on soil water transport and water suction changes, the characteristics of soil water transport and distribution under different straw application depths were simulated by laboratory simulation test. Corn straw was crushed into small sections of less than 5 mm and stored in dry space. For the given application depth, straw was mixed with dry soil evenly with 1% application ratio. Five treatments were set up:no straw returning (CK), straw application depth of 15 cm (S15), straw application depth of 20 cm (S20), straw application depth of 25 cm(S25), straw application depth of 30 cm (S30). Soil water suction value was measured by micro-tensiometer(T5). The results showed that the application depth of straw had an effect on soil water infiltration characteristics. With the increase of straw application depth, the transport distance of wetting front and the cumulative water infiltration amount decreased. The influence of straw application depth on wetting front migration was obvious. At the same infiltration depth, the moisture content of soil layer containing straw increased significantly than that without straw layer. Straw application depth had an important impact on soil water suction, the changing trend of soil water suction values at different soil depth was roughly the same. Different straw application depth led to the difference of soil water suction peak and peak time under the same soil layer depth. The deeper straw application was applied, the greater the peak value of soil water suction and the longer the time to reach the peak value.