The invention provides a small-sized distributed combined solar cooling heating and power system and an application method thereof. The heat-transfer medium outlet of a focusing collector (1) is connected with an ORC power generation system (2), a heating system (3) and a cooling system (4) by pipelines via a first regulating valve (5), a second regulating valve (6) and a third regulating valve (7) respectively; and the mirror plane of a reflector (8) of the focusing collector (1) is a cambered surface. The small-sized distributed combined cooling heating and power system utilizes solar thermal energy to realize cooling heating and power generation, and can dynamically regulate the ratio of three energies (cooling, heating and power) according to different periods and different energy consumptions of users.