Considering the influence of core rotation, we calculate the recurrence spectra of Rydberg NO molecules in the strong external magnetic field by using the molecular closed orbit theory and the multichannel quantum defect theory. The results indicate that the complicated recurrence spectra can be explained by the molecular closed orbit theory including the molecular core-scattering. Not only the elastic core-scattering effect arising from the intrachannel scattering, but also the inelastic core-scattering effect arising from the interchannel scattering is vital to the dynamical properties of the Rydberg molecule. Especially on the larger scaled action, the contribution of core-scattering is more crucial than that of the primary closed orbits and their repetition, and affects the dynamical properties of system to a large extent.