Objective To evaluate the efficacy of sequential therapy with tumor necrosis factor inhibitor (TNFi) and conventional synthesis disease-modifying anti-rheumatic drugs (csDMARDs) in delaying imaging progress and maintaining function of the affected hip in ankylosing spondylitis (AS) patients. Methods AS patients with hip pain and limited activity were enrolled in this study. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were measured regularly, and ankylosing spondylitis disease activity score based on C-reactive protein (ASDAS_CRP) was performed to evaluate the disease activity. Etanercept (a TNFi) and csDMARDs were used sequentially according to the disease activity. Before sequential therapy and 3, 6 and 12 months after sequential therapy, the subjective symptoms were assessed by visual analogue scale, the condition was assessed using ASDAS_CRP and Bath ankylosing spondylitis disease activity index (BASDAI), the body function was assessed using Bath ankylosing spondylitis function index (BASFI), and the imaging changes of hip joint lesions were assessed using Bath ankylosing spondylitis radiology index-hip (BASRI-hip) and minimum joint space width (mJSW). Results A total of 51 patients (38 males[74.5%] and 13 females[25.5%]) aged from 10-56 years were enrolled, and the onset age was 9-40 years. No hip arthroplasty was performed due to limited hip function or further damage of hip joint structure. Based on assessments in ankylosing spondylitis (ASAS) Work Group criteria, 70.59% (36/51), 84.31% (43/51) and 96.08% (49/51) patients met the ASAS20 criteria and 58.82% (30/51), 78.43% (40/51) and 86.27% (44/51) patients met the ASAS40 criteria 3, 6 and 12 months after sequential therapy, respectively. At the follow-up points of 3, 6 and 12 months, the overall trends of CRP level and ESR, patient global assessment score, ASDAS_CRP, BASDAI score and BASFI score were significantly decreased (all P<0.05), while the overall trends of BASRI score and mJSW were not significantly changed (both P>0.05). Conclusion Sequential therapy with etanercept (a TNFi) and csDMARDs can effectively inhibit inflammation, avoid further damage of hip joint, improve joint function, and keep the hip joint space width in AS patients.