With the rapid growth of artificial intelligence in recent years, picture caption has steadily grabbed the attention of many artificial intelligence researchers and has become an important study topic. alluring and arduous task. Image captioning and spontaneously generating natural human language captions according to the content observed in the above-captured image is an important part of scene understanding, which requires the knowledge of computer vision and natural language processing. The operation of the image caption generator is far-reaching and eloquent, for instance, the realization of human-computer interactions. This paper encapsulates methods and focuses on the attention mechanism, which plays a vital role in computer vision and is recently used in image caption generation tasks.