The invention discloses an underground movable inert fire prevention and extinguishing material phase change generator. The front end of a shell is provided with a shower head water/air feeding groove, the rear end of the shell is provided with a water/gas discharge collector groove, multiple spiral copper pipes are connected between the shower head water/air feeding groove and the water/gas discharge collector groove in the shell, the front end of each spiral copper pipe is provided with an embedded constant flow valve, the side wall of the shell is provided with a charging hole and an inert gas outlet, and the inert gas outlet is provided with a constant flow valve and flowmeter. The shower head water/air feeding groove is provided with a spiral flow guide groove. The side wall of the shell is provided with a pressure meter, an exhaust valve and a safety valve. A shower head water/air inlet is connected with a water inlet pipe and an air inlet pipe through a three-way valve. A shower head water/air outlet is connected with a water outlet pipe and an air outlet pipe through a three-way valve. Solid state inert fire prevention and extinguishing material phase change is utilized for obtaining inert gas, an underground coal mine water pipe or air pipe is directly utilized for providing heat needed by the inert fire prevention and extinguishing material for obtaining insert gas, and no power source is adopted, so that safety and reliability are higher, and energy is saved.