Abstract: A new visual pullout test model device is developed, which can be used to carry out pullout tests on geosynthetics and soil. The device improves the loading system and the reaction system, and realizes the pullout interface visualization and data acquisition automation. It can measure the displacements of geosynthetics with different embedment lengths, and obtain the deformation values of geosynthetics. The reinforcement mechanism and displacement evolution of interface soil in the process of reinforcement soil interface interaction are studied. The newly developed test equipment is used to carry out the pullout tests on coarse grained soil and geogrid. The results show that the greater the vertical pressure, the smaller the soil grid strain, the more significant the interfacial friction between soil and geogrid and the embedment effect. Two modes of translational and rotational displacements can be found on the reinforcement soil interface, and the interface particles form a stable soil displacement concentrated zone.