<p>This study systematically investigated the influence mechanism of single physical field and multi-physical field coupling on the degassing behavior of heat-resistant aluminum alloy melts. Through comparative experiments, it was found that under a melt temperature of 727&#xa0;°C, the three-field collaborative treatment scheme of ultrasonic (power 1500 W, frequency 20kHz)—electromagnetic (current intensity 60A)—low-pressure environment (dynamic pressure 0.5kPa) could achieve the best degassing effect. Quantitative analysis showed that after treatment with this optimized process, the porosity volume fraction of the ingot decreased significantly from the original 0.312–0.014 cm³/100g. This was mainly attributed to the combined effect mechanism of ultrasonic cavitation promoting bubble nucleation, electromagnetic stirring enhancing melt convection, and vacuum environment reducing gas partial pressure. Correspondingly, the mechanical properties of the material were significantly improved. The room temperature tensile test results showed that the tensile strength increased from the initial 222–268 MPa. This performance improvement was significantly correlated with the microstructure evolution characteristics such as the reduction of porosity, densification of the microstructure, and the uniform distribution and reduction in size of dimples observed in the SEM fracture surface. The above results indicate that the multi-physical field collaborative treatment improves the degassing effect of the melt, providing important experimental basis and theoretical reference for the development of high-performance heat-resistant aluminum alloy melt treatment processes.</p> Graphical Abstract <p></p>