In order to study the temperature and radiation of the deep-water ground blowout flame, the safety range of the blowout process was predicted. Based on this, the theoretical calculation model of the thermal radiation intensity of the jet flame was established, and the thermal radiation distribution of the jet flame was simulated by the finite element analysis software. According to the actual nozzle sink in the deep water test site, the influence of different pipe diameters and different yields on the thermal radiation distribution of the jet flame was studied when the arm length is 25 meters. The results show these as follows. The flame is spindle-shaped, and the temperature and radiation in the center of the flame are the largest. As the distance increases, the temperature and radiation gradually decrease. Under the same output, with the increase of the nozzle diameter, the axial and radial range sizes of the radiation area above 100 kW/m² gradually increase, and the maximum radiation amount also gradually increases. Under the same nozzle diameter, with the increase of output, the temperature and radiation increase to a certain extent as a whole. The overall temperature and radiation increased first, then decreased after reaching the peak, and then increased slightly. The relevant research results provide some theoretical support for the safety evaluation of deep-water test ground blow off.