In recent years, countries around the world have been committed to improving the low detectability performance of ships. Radar cross section is a key indicator for measuring the reflection intensity of incident radar waves by targets. The larger the value, the stronger the echo, and the easier it is for targets to be detected. Therefore, reducing the radar cross section area has become an important indicator for measuring the stealth capability of warships. Currently, researchers mainly reduce radar cross section through the following three methods. Adjust and optimize the geometric shape. In terms of exterior design, traditional shipborne weapons are often exposed on the surface of the ship, and these protrusions are more easily detected by the enemy's radar. Therefore, military researchers usually design buildings above the deck in the shape of arcs, parabolas, or inclined polyhedra. For example, the Russian 22350 multi-purpose stealth frigate adopts a fully enclosed stealth design, effectively reducing the radar scattering cross-sectional area. Combination application of stealth coatings. In order to better achieve the "stealth" effect of warships, researchers apply different types of coatings on the surface of warships. These coatings are stacked together, enabling the warship to achieve low detectability across the entire frequency range. The British Type 45 destroyer adopts radar absorbing material coating and infrared suppression coating, and the warship has a significant "stealth" effect. Real time control of phase frequency. The control system installed on the ship will generate an opposite frequency band based on the incident radar waves. After being transmitted through the antenna, they cancel each other out, thereby reducing the radar scattering cross-sectional area and enhancing the "stealth" effect. Although this advanced technology is still in the experimental stage, the experimental results have fully verified its superior performance and feasibility. It can be seen that the "stealth" technology of warships is developing towards low detectability in all frequency bands and multiple fields. In the future, with the innovative application of high-performance materials and artificial intelligence technology, the stealth capability of warships will be further enhanced. (New Society)