Objective. To investigate the clinical value of high-frequency ultrasound in psoriatic arthritis (PSA). The study subjects were 32 outpatients and inpatients with PSA who were pathologically diagnosed from January 2018 to September 2020, including 11 males and 21 females, aged 25–70 years old, with an average of (49.8 ± 14.0) years old. All patients underwent ultrasound and physical examination, including the small joints of the hands and feet on both sides, nails, and the main attachment points of the lower limbs (quadriceps tendon, patellar ligament, Achilles tendon, and plantar fascia attachment). The involvement of these joints, attachment points, and nails was observed and counted, respectively, and statistically analyzed. Results. Physical examination revealed 406 (406/1792, 22.66%) joint lesions, 79 (79/320, 24.69%) attachment inflammation, and 84 (84/320, 26.25%) nail lesions. Ultrasonography revealed 492 (492/1792, 27.46%) joint lesions, 166 (166/320, 51.88%) attachment inflammation, and 203 (203/320, 63.44%) nail lesions. The positive rate of ultrasound examination was higher than that of physical examination (
P
<
0.001
). Conclusion. Ultrasonography can detect joint, attachment, and nail lesions earlier than physical examination in patients with PSA. Ultrasonography is of great value in the diagnosis of PSA.