Taking conventional tillage and direct drilling without mulch as CK, this paper discussed water consumption characteristics of summer corn under no tillage with mulch. Results show that water consumption with less differences among the treatments. Tillage did not increase or reduce water consumption of summer corn too much. Compared with conventional tillage and direct drilling, water use of summer corn under no tillage with mulch varied in time and space scale, i.e., no tillage with mulch reduced water use in summer corn and increased water consumption in late phase; and decreased soil evaporation and increased corn's transpiration, which increase summer corn yield and water use efficiency.