Particle breakage often occurs in the fields of geological, geotechnical and hydraulic engineering like rock avalanche, landslides and high earth-rock dam, which affects the design and countermeasures of relevant en-gineering structures. Investigation of particle breakage's effect on mechanical behaviors of granular soils has always been the hotspot within the community of particulate materials. In this study, a coupled finite element method (FEM) and discrete element method (DEM) modeling has been developed to tackle boundary value problems (BVPs) related with particle breakage. In the method, the particle breakage simulation is implemented in DEM through the conventional bonded particle modeling (BPM), while the stress-strain characteristics of representative volume element (RVE) captured by DEM is directly transmitted into the FEM solver to avoid the complicated and phenomenological constitutive equations incorporating into particle breakage. As an illustra-tion, we apply the proposed multiscale modeling to investigating mechanical behaviors of quartz sands subjected to particle breakage through the high confining pressure biaxial compression simulation. And effects of particle strength, particle shape and confining pressure on particle breakage characteristics and further mechanical be-haviors of quartz sands are also discussed accompanied with the underlying micromechanisms. Results demonstrate that the coupled FEM-DEM modeling can be able to deal with the complex geomechanics problems involving particle breakage.