Objective To evaluate the nail damage and extensor tendon changes in patients with psoriasis by color Doppler high frequency ultrasound and energy Doppler ultrasound, and to explore the clinical value of ultrasound in the diagnosis of nail damage in patients with arthritic psoriasis. Methods A total of 86 patients with psoriasis diagnosed in our hospital from June 2016 to June 2019 were analyzed retrospectively, including 46 patients with arthropathy psoriasis (PsA group) and 40 patients with psoriasis vulgaris (Ps group). 30 healthy subjects without nail damage in the same period were selected as the control group. All patients were examined by physical examination, and the general clinical data were recorded. The thickness of nail deck, nail bed, nail matrix and extensor tendon were measured by high frequency ultrasound. Wortsman classification was used to classify fingernails. PD was used to evaluate the local inflammation of fingernails. Results The severity of psoriasis in Ps group was higher than that in PsA group, and the inflammatory index in PsA group was higher than that in Ps group. The deck, nail bed and nail matrix of the two groups were thickened, and the thickness of finger extensor tendon was larger than that of the control group. Type I was the most common Wortsman classification in Ps group, while type II was more common in PsA group. PD showed that the PD signal in nail bed and nail matrix was significantly enhanced in both groups, and the PD signal in the tendon of distal fingernail joint was significantly enhanced in both groups. Conclusion Color Doppler high frequency ultrasound can evaluate the structure and morphology of nail in patients with psoriasis, reflect the local inflammation of nail bed, and has important value in the occurrence and development of arthropathy psoriasis.