The elbow posterolateral rotatory instability (PLRI) is the most common type of elbow instability.Elbow PLRI cases caused by traffic accidents and sports are becoming increasingly common.It is very important to understand the elbow anatomy,biomechanics and pathogenesis of the PLRI,to master the treatment principles of elbow PLRI and choose the appropriate therapeutic regimen for the diagnosis,treatment,and prevention of missed diagnosis and misdiagnosis of elbow PLRI so as to restore the function at early time.This article reviews the biomechanics,diagnosis and treatment of elbow PLRI,in order to provide the basis for future investigation of large sample survey or long-term follow-up study,to obtain better treatment effects for the elbow PLRI.