Ankylosing spondylitis is a refractory autoimmune disease, and heterotopic ossification is one of the most important pathological features.The mechanism of heterotopic ossification in ankylosing spondylitis involves many aspects, including ossification-related genes, ossification-related factors, ossification-related cells, ossification signaling pathways, and mechanical stress.This article elaborates the pathogenesis of heterotopic ossification in ankylosing spondylitis from different aspects of multiple channels, pathways, targets, and factors, hoping to provide reference for expanding clinical and basic research and in-depth understanding of ankylosing spondylitis.