With the information field continuously evolving, B5G and 6G have been introduced, and the development of digital communication has entered a stage of faster updates. To adapt to higher-speed communication and more diverse channels, different modulation formats have been proposed and applied in different environments. The purpose of changing modulation format in different time and channels is to maximize the channel utilization. However, the modulation format changed at the transmitter is unknown to the receiver, which does not facilitate the connection between different communication subsystems, thus affecting the construction of a large-scale air-space-ground-sea integrated communication network. Therefore, modulation format recognition may be key to solving this problem. Because artificial intelligence (AI) has great advantages in signal processing and classification based on feature extraction, modulation format recognition based on feature extraction combined with AI classification algorithm has great research and practical value. This study introduces several methods based on feature extraction and AI and analyzes, discusses, and summarizes their application in the communication field.