In order to study the relations between the root-water-uptake of crop and soil water salt transport in root zones，field experiments were conducted under the conditions of spring maize growth in Shiyang River Basin of Gansu province.The field experiments were carried out in test-pits.It was introduced into the root-water-uptake model，which was proposed by Feddes.During the growing period of spring maize，the seven time periods were selected to study the root-water-uptake of spring maize.Fresh water，3 g/L and 6 g/L irrigation treatment were set up in field experiments.The root-water-uptake content of each treatments at different period was calculated using water balance equation.The parameter(p)of salt stress reduction function was optimized by the least square method and the parameter(p)was 1.397.The root-water-uptake content of 3 g/L and 6 g/L irrigation treatment was simulated and compared with measured value.The correlation coefficient was above 0.99 and the error between the simulated and measured values was within the allowable error range of 15%.It establishes the root-water-uptake model of spring maize under salt stress conditions.This model is conducive to understanding of the law of soil salt movement under spring maize growth.