The most common complications of femur fracture are infection, malunion, non-union of fracture, deep vein thrombosis of lower limb and so on. 1. Infection: due to heavy trauma, open wound, surgical incision, etc., infection may occur, manifested as redness, swelling, heat and pain in the affected limb, affecting the healing of wound and fracture, and may cause osteomyelitis if it continues to develop. 2. Deformity healing: due to untimely treatment, improper surgery or displacement of internal fixation, etc., it can lead to deformity healing of femur, such as angular deformity and shortening deformity. It can be manifested as unequal length of both lower limbs and unstable walking. 3. Fracture non-healing: due to poor blood supply to the fracture site, poor fixation after fracture or loose internal fixation and other factors, it can also lead to the symptoms of fracture non-healing. It is manifested as edema of the affected limb, persistent pain without relief, and X-ray manifestation of widened interval and sclerosis of the fracture break. 4. Lower extremity deep vein thrombosis: because of the need for bed rest after the fracture, the activity is reduced, resulting in lower extremity blood flow slowing down, as well as the fracture end of the fat particles into the blood circulation, which can easily lead to the formation of deep vein thrombosis of the lower extremity. The phenomenon of swelling and pain in the lower limbs occurs. After the occurrence of femur fracture, the patient should actively cooperate with the doctor for examination and treatment, so as not to delay the condition.