Gravel soil has excellent engineering properties， so it is of great significance to understand its characteristics for engineering construction.In order to study the mechanical properties of crushed stone soil，the direct shear test of large-scale crushed stone soil was carried out in laboratory，and the conditions of different moisture content and stone content were considered.The results show that the moisture content weakens the shear strength of the crushed rock，while the stone content and normal stress strengthen the shear strength of the crushed rock.The cohesion and internal friction angle of gravel soil decrease with the increase of moisture content.With the increase of stone content，the cohesion of gravel soil shows a tendency of decreasing first，then increasing and then decreasing，and the internal friction angle increases with the increase of stone content.