Abstract: The strain transfer mechanism between fiber Bragg grating sensor (FBGs) and matrix, which is the basic problem of cure monitoring, was explored by combining of experimental and numerical analysis. Firstly, curing kinetics, thermal expansion, chemical shrinkage and glass transition behavior of the resin were characterized. Then, the developments of temperature and strain were monitored by thermocouple and FBGs during the curing process of epoxy resin. Finally, the thermal-chemical-mechanical multi-field coupling numerical analysis was used to simulate the curing process. The interface transfer mechanism was discussed by comparing the results of pure resin model, FBGs model with binding constraint and FBSs model with cohesive behavior. The results indicate that the strain monitored by FBGs is significantly smaller than that of the resin due to the shear lag effect and interface slip behavior at the early curing stage, and the shear lag effect plays a dominant role. The interfacial strain transfer mechanism during curing process can be described properly by cohesive behavior, and the error between numerical prediction and experimental value is small.