The effect of strain on the electronic structure and optical properties of Mo2C(001) surface were studied by the firstprinciples method. The band structure results show that Mo2C(001) surface is an indirect band gap semiconductor, and the band gap decreases with compressive strain and tensile strain increasing. When the strain is -20%, Mo2C surface (001) changes from an indirect band gap semiconductor to metal. When the strain is -20%, -15%, -10%, -5%, 0%, 5%, 10%, 15% and 20%, the band gap is 0 eV, 0.162 eV, 0.376 eV, 0.574 eV, 0.696 eV, 0.708 eV, 0.604 eV, 0.437 eV and 0.309 eV, respectively. The reason for the change of band gap is mainly that, the electrons of Mo 4p, 4d, 5s and C 3p states become sensitive to each other are excited under difference strains, and the activity is enhanced. The results valence band top is changed among the points of G, A, L and M, and the conduction band bottom is changed between the points K and H in Brillouin region. When the strain gradually changes from -15% to 20%, the first peak of the absorption spectrum gradually decreases, the photoelectron energy corresponding to the first peak decreases, and the absorption band edge moves to the low energy direction, indicating that the optical absorption increases with the increase of compressive strain, and the absorption band edge moves to the low energy direction with the increase of tensile strain. At the same time, other optical properties show similar changes with the strain change. The calculation results of optical properties show that the strain effectively adjust the optical absorption characteristics. The research results provide theoretical support for the application of Mo2C (001) as new optoelectronic material.