The invention discloses a nuclear reactor and solar energy photo-thermal power generation combined system which comprises a first circulation loop, a second circulation loop and a third circulation loop. The first circulation loop is provided with a nuclear reactor and a heat exchanger. Heat generated by the nuclear reactor is transmitted into the heat exchanger through a circulation pipeline on the first circulation loop. A solar heat collecting module and a steam generator are arranged on the second circulation loop. Heat generated by the solar heat collecting module and the nuclear reactoris transmitted to the steam generator through the second circulation loop to generate steam, and the steam is conveyed to a steam drive turbine on the third circulation loop. The steam drive turbine drives a power generator to generate power. By means of the nuclear reactor and solar energy photo-thermal power generation combined system, the nuclear reactor is combined with solar photo-thermal power generation, the nuclear reactor and solar energy photo-thermal power generation combined system is formed, the problem that solar energy photo-thermal power generation cannot be achieved at night,and consequently a unit is frequently started and stopped is solved, and the solar energy photo-thermal power generation stability is improved.