A two-year (2011—2012 and 2013—2014) field experiment was carried out at Yuzhou City of Henan Province, China. The experiment data were used to calibrate and validate the RZWQM (Root zone water quality model) model for its simulation of soil water distributions, above ground biomass and wheat yield under different tillage treatments (conventional tillage, no-tillage and subsoil tillage). The calibrated RZWQM model was then used to simulate the dynamics of soil water storage in the 0~100cm soil layer, crop water consumption, water balance and water use efficiency when conventional tillage was transformed to four types of conservation tillage patterns, including no-tillage, no-tillage with straw mulching, subsoil, and subsoil with straw mulching. The root mean square errors of soil water content were 0.009~0.025cm3/cm3 for model calibration and 0.005~0.054cm3/cm3 for model validation, respectively. Simulation results showed that the RZWQM model was able to simulate the dynamics of soil water content when tillage method was transformed from conventional tillage to the four conservation tillage patterns. Wheat yield was the highest for transformation of conventional tillage to no-tillage, and the water use efficiency could reach 19.3kg/（hm2·mm）. Therefore, no-tillage was the best conservation tillage method for soil moisture conservation among the four conservation tillage patterns.