Myasthenia gravis is an autoimmune neuromuscular junction disorder primarily mediated by autoantibodies against the acetylcholine receptor (AChR). It is now widely recognized that the total titer of anti-AChR antibodies does not correlate directly with clinical severity and shows significant interindividual variability. This review focuses on the structure of the AChR, the three major pathogenic mechanisms mediated by anti-AChR antibodies, the pathogenic differences associated with distinct antigenic epitopes, the characteristics of various immunoglobulin subclasses, and the limitations of current antibody detection methods. It further explores future directions in antibody profiling and functional assessment. By systematically analyzing the complexity and heterogeneity of anti-AChR antibodies, this article underscores the critical role of precision medicine in the management of myasthenia gravis.