Infrared stealth capability is also one of the key focuses for future advanced stealth fighters. Relevant studies on aircraft infrared radiation characteristics (Mahulikar et al. 2007; Sang and Zhang 2013; Rao and Mahulikar 2002) show that the engine exhaust system is the main source of infrared radiation on the aircraft, producing more than 95% of the infrared signature in the tailward direction of the aircraft. Serpentine nozzles can effectively suppress the infrared radiation intensity of the exhaust system, thereby improving the aircraft’s infrared stealth capability. Serpentine nozzle technology has been listed as one of the key technologies for advanced stealth fighters (Sang and Zhang 2013; Zhang et al. 2014). The design of serpentine nozzles involves many geometric parameters, and changes in geometric parameters will alter the profile structure of the serpentine nozzle, thus affecting the flow field characteristics and infrared radiation characteristics of the serpentine nozzle. Therefore, in the design of serpentine nozzles, both aerodynamic performance and infrared radiation characteristics need to be considered simultaneously in order to achieve the goal of significantly suppressing infrared radiation characteristics while maintaining high aerodynamic performance of the nozzle. This chapter uses numerical simulation methods to analyze the distribution characteristics of infrared radiation intensity of serpentine nozzles and the mechanisms generating it, studies the influence rules of geometric design parameters on the infrared radiation characteristics of serpentine nozzles, compares the differences in infrared radiation characteristics of serpentine nozzles under different inlet conditions; from the perspective of infrared stealth, carries out research on low-infrared radiation design criteria for serpentine nozzles; based on approximate modeling techniques and multi-objective optimization algorithms for serpentine nozzles, performs aerodynamic/infrared multi-objective optimization design with the goals of high aerodynamic performance and low infrared radiation intensity.