This study investigates the effect of TIG weld pool temperature on the microstructure and mechanical properties of crack-repaired joints in 7072 aluminum alloy. To address poor temperature stability and slow response in indirect temperature control during TIG welding by adjusting the parameters, a new closed-loop molten pool temperature control method is proposed. Experimental comparisons were conducted to evaluate its effectiveness. The results show that using real-time molten pool temperature as direct feedback allows the welding current to be adjusted dynamically. This approach enables precise control of heat input. It also achieves real-time tracking and stable regulation of the molten pool temperature during welding. Temperature-controlled welding yields a more uniform joint microstructure with reduced porosity. Notably, the joint exhibits optimal comprehensive mechanical properties at 1825 °C, with a tensile strength of 328 MPa and an elongation of 9.9%. Overall, precise control of the TIG weld pool temperature effectively improves the quality and performance uniformity of aluminum alloy crack repairs.