Objective To analyze the values of magnetic resonance imaging (MRI) optimization sequence in the diagnosis of scapulohumeral periarthritis and rotator cuff injury. Methods The clinical data of 69 cases of patients with scapulohumeral periarthritis or rotator cuff injury diagnosed by arthroscopy in our hospital from May 2015 to May 2017 were analyzed retrospectively. The GE 1.5T MRI and joint coils were used to carry out the scanning of routine sequence and optimization sequence, including transverse axial, oblique coronal and oblique sagittal positions. The joint injury, the degree and range of injury were observed to perform the diagnosis of scapulohumeral periarthritis and rotator cuff injury. Results Among 69 cases of patients, there were 22 cases of scapulohumeral periarthritis and 47 cases of rotator cuff injury by arthroscopic diagnosis. The accuracy rate, the sensitivity and the specificity were 97.10% (67/69), 95.45% (21/22) and 97.87% (46/47) of MRI optimization sequence in the diagnosis of scapulohumeral periarthritis and were 98.55% (68/69), 97.87% (46/47) and 100% (22/22) of MRI optimization sequence in the diagnosis of rotator cuff injury. There were significant differences in the positive detection rate between T1WI and T2WI-STIR sequences (P<0.05), and the results of optimization sequence scanning showed that the positive detection rate was good in the supraspinatus tendon oblique coronal, oblique sagittal and transverse axial T2WI-STIR sequences, and the positive detection rate was good in the posterior supraspinatus tendon oblique coronal and transverse axial T2WI-STIR sequences, and the positive detection rate was good in the telescope tendon and subscapular tendon transverse axial T1WI T2WI-STIR sequences. Conclusion MRI is an important method for clinical diagnosis of scapulohumeral periarthritis and rotator cuff injury. The optimization sequence scanning can reflect different pathological features and help to improve diagnostic accuracy.