Abstract: A combined power generation system and method of a small fluoride-salt-cooled high-temperature reactor and solar tower is provided, which belongs to the field of new energy and renewable energy application and includes: a nuclear reactor power generation system, a solar tower power generation system and a heat compensation system. Both the nuclear reactor power generation system and the solar tower power generation system adopt supercritical carbon dioxide Brayton cycle system to generate electricity efficiently; molten salt pool in the nuclear reactor power generation system stores high-temperature heat from the modular reactor, and multi-stage temperature heat is utilized for generating power and compensating heat required by the solar tower power generation system.