Abstract: Metallized film capacitors are core components of the converter valves in flexible high-voltage direct-current (HVDC) transmission systems. Mastering the self-healing parameters of metallized films under complex operating conditions is crucial for the development of high-performance capacitors and improving energy transmission efficiency. Based on the actual operating conditions of metallized film capacitors, this paper utilizes a multi-physical field self-healing testing platform to conduct self-healing characteristic tests under the combined effects of electrical, thermal, and mechanical stresses. The study reveals the interactive effects of voltage, temperature, and pressure on the self-healing behavior of metallized films. It is found that as the temperature increases, the impact of voltage on self-healing becomes more remarkable; while as the pressure rises, the impact of voltage on self-healing gradually diminishes. When the pressure exceeds 4 MPa, the effect of voltage on self-healing becomes negligible. Through statistical analysis of self-healing characteristics, this paper establishes a correlation between self-healing parameters and concludes that the self-healing area and the number of self-healing points are negatively correlated. Specifically, when the number of self-healing points in the effective area increases from 1 cm^–2 to 30 cm^–2, the average area of a single self-healing point decreases from 16 mm² to 1 mm². Furthermore, self-healing current peaks, self-healing time, and self-healing voltage are positively correlated. When the voltage reaches 3.5 kV, the self-healing time can reach 4 μs, and the self-healing current peak can reach 5 A. The self-healing energy follows a power function with an exponent of 2.316 relative to the self-healing voltage. Based on the established correlation between self-healing parameters, this paper also proposes a rapid estimation method for self-healing energy. The research involves key characteristic parameters and criteria for the performance of metallized film materials, providing valuable data supports for the optimized design of metallized film capacitors.