Objective: Hip ankylosis is a prevalent condition in patients with Ankylosing spondylitis (AS) that can significantly impact their psychological well-being. This study aimed to investigate the impact of Total Hip Arthroplasty (THA) on anxiety and depression among AS patients. Methods: 62 AS patients undergoing primary THA were recruited and separated into two groups based on preoperative hip motion. The 40 patients with hip mobility of 0° were assigned to group A, and others were assigned to group NA. Self-rating Anxiety Scale (SAS), Self-rating Depression scale (SDS), Harris hip scores (HHS) and 36-Item Short Form Survey (SF-36) were obtained one week before and there, six and twelve months after THA. Results: The study found that AS patients in group A had significantly higher levels of anxiety and depression (SAS score = 75.05± 2.79, SDS index score = 0.74± 0.02) compared to group B (SAS score = 54.58± 3.35, SDS index score= 0.64± 0.03, P=0.01). However, both groups showed significant improvements in anxiety and depression scores from there to twelve months after THA (P< 0.001). Correlation analyses revealed that the improvement in group NA was associated with hip pain relief (p< 0.001), while the improvement in group A was related to joint function, disease duration, age at THA and spine imaging lesions (p< 0.001). Conclusion: Some degree of anxiety and depression was present in both groups of AS patients. Levels of depression and anxiety were higher in patients with combined hip ankylosis. And their improvement was associated with improved hip function and quality of life after THA. Hip pain relief played a significant role in patients without hip joint ankylosis. The impact of the degree of lesion on spinal imaging on psychological status needs to be considered in both groups.