The thermal transport properties of electrons in graphene nanoribbon (GNR) subjected to strain fields are studied by non-equilibrium Greens function approach.The results show that the stretching of the carbon-carbon bond in strained GNR can enhance the ballistic thermal conductance of electrons.The enhancement originates from that the change of C-C bond length can modulate the nearest-neighbour π-orbital overlap and reduce the threshold energies of electron transport modes.