During the high-speed flight of aircraft, raindrop impact erosion causes significant damage to surface materials, thereby seriously affecting flight performance and structural safety. This paper is aimed to systematically review the mechanical mechanism, key influencing factors, and progress in corresponding protection technologies of high-speed raindrop impact erosion. In terms of experiments, current studies mainly rely on devices such as wind tunnels, rocket sleds, and rotating arms to construct simulated environments of real rain fields. Meanwhile, high-speed photography is used to record the dynamic erosion process, and laser velocimetry is employed to obtain raindrop impact velocity, thus achieving multi-dimensional observation of erosion behavior. In terms of numerical simulation, it was focused on introducing mainstream simulation techniques such as the finite element method and the smoothed particle hydrodynamics method. Additionally, an overview was provided of existing research methods and outcomes, which primarily involve establishing liquid-solid coupling models to analyze the propagation patterns of stress waves and the dynamic response characteristics of materials during impact processes. The research results show that raindrop impact velocity, impact angle, and mechanical properties of materials are the key factors affecting the erosion rate. Based on the actual flight envelope parameters of aircraft, targeted optimization design of rain erosion resistance performance can be carried out, which can provide a theoretical basis and technical support for improving the service safety of aircraft in harsh meteorological environments.