3D collective cell migration in extracellular matrix (ECM) is among one of the most significant topics in developmental biology, cancer progression and immune response while its mechanisms remain to be elusive. Inspired by experimental observation that oriented collagen guides cancer cell intraversation, we develop a computational framework to investigate force generation and propagation in heterogeneous ECM containing migrating breast cancer cells. Specifically, a correspondence between microstructure and micromechanics of cellularized-3D-ECM is established. By extracting geometrical and topological information of ECM structure from limited confocal images, collagen networks with different morphologies are reconstructed as ECM for migrating cells. Then, a force network of the given ECM is established for identifying the mechanical feedback between isolated migrating cell and local ECM. The single cell migration is predicted. Furthermore, the migrating cells regulate and coordinate with one another via ECM mediated force generation and propagation, leading to possible collective invasive behaviors in vivo.