Method for building artificial heat reservoir of hot dry rock through cooperation of microwave radiation and dry ice jet flow

The invention discloses a method for constructing a hot dry rock artificial heat reservoir through cooperation of microwave radiation and dry ice jet flow, and belongs to the field of construction of hot dry rock geothermal artificial heat reservoirs. Aiming at the deep dry hot rock with low air void ratio and low permeability, the artificial heat reservoir with a large-range heat exchange area is built in the dry hot rock with high efficiency and low cost by applying microwave radiation and dry ice jet technologies. The mechanical property of the hot dry rock body can be weakened by heating the hot dry rock body through microwave radiation, and the pressure stress needed by fracture is reduced. And particle dry ice is pumped into the radiated rock mass, so that the dry ice impacts the rock wall at a high speed in a jet flow form. The rock mass bears large pressure stress while forming a temperature gradient and is fractured to form a fissure net. And under continuous circulating fracturing, cracks are contin