Objective To analyze and compare the diagnostic efficacy of musculoskeletal ultrasound, X-ray, CT, magnetic resonance (MRI) and laboratory test indexes in the diagnosis of ankylosing spondylitis (AS), and to explore the clinical application value of musculoskeletal ultrasound in the diagnosis of AS..Methods A total of 82 patients with AS in our hospital from February 2017 to December 2020 were selected. All patients underwent musculo-skeletal ultrasound, X-ray, CT, MRI, serum hypersensitive C-reactive protein and erythrocytes sedimentation rate examinations. According to the results of human leukocyte antigen (HLA-B27), they were divided into positive group (case group) and negative group (control group). To analyze and compare the efficacy of musculoskeletal ultrasound and other examination methods in the clinical diagnosis of AS.Results The 82 patients were divided into case group (n = 69) and control group (n = 13) according to HLA-B27 results. Ultrasound, X-ray, CT and MRI had statistical significance in the diagnosis of AS (P < 0.05). There was no significant difference in the detection rate of AS between ultrasound, X-ray, CT and MRI (P > 0.05). There was no significant difference in the detection rate between ultrasound and MRI in the diagnosis of AS in the inflammatory stage (P > 0.05). There was no statistical significance between ultrasound and laboratory inflammatory indicators in the diagnosis of sacroiliac joint inflammation (P > 0.05). .Conclusion Musculoskeletal ultrasound can be used AS an important imaging method for the diagnosis of AS, especially in the inflammatory stage of AS, and the detection rate of ultrasound is comparable to that of MRI.