In order to reveal the performance mechanism of biochar for saving water by protecting fertilizer under different soil textures (based on the peanut shell biochar on sandy soil), we researched silt loam hydraulic characteristic parameters and the characteristic of water. Different biochar treatments (0, 0.05, 0.1, 0.15 g g^-1) of density, porosity, saturated hydraulic conductivity, saturated water capacity, and soil water retention curve were determined using the cutting ring, constant-head, and pressure membrane methods. The results show that the application of biochar can change sandy soil and silt loam structures. Sandy soil and silt loam bulk density decreased and sandy soil effective porosity increased with the increase of adding biochar, and all treatments of silt loam total porosity from big to small in turn 0.15, 0, 0.05, 0.1 g g^-1. Adding peanut shell biochar inhibited sandy soil water infiltration, and increased soil water-holding capacity and silt loam water-holding capacity in 0.15 g g^-1 processing over control by 0.1, 0.05 g g^-1 processing. In the same water potential cases for increasing biochar content, sandy soil water-holding performance enhancements, and silt loam hold water effect are not obvious. Therefore, the peanut shell biochar on the impact of different texture soil hydraulic parameters is inconsistent, and improving the soil structure and moisture performance effects of sandy soil is remarkable. The results of the study for biochar in sandy soil amelioration and utilization of water has a very important meaning and theoretical value.