X-ray magnetic circular dichroism (XMCD) in the absorption of the single-crystal iron thin film deposited epitaxially on MgO substrate is studied to get the spin and orbital moment. The experiments show that along with different crystal axes, the change of orbital moment of Fe atoms is about 600%, the change of the spin moment is only about 50%, but the change of total moment is not so large. Researching the anisotropy by means of routine methods, the relation between the magnetic moment and the anisotropy of the thin film is studied.