Fascia iliaca compartment block (FICB) relies on the diffusion of local anesthetics into the femoral nerve, lateral femoral cutaneous nerve, and obturator nerve in the fascia iliaca space to achieve analgesia in its innervated area. Ultrasound-guided FICB is widely used in hip and knee arthroplasty, femoral fracture and patellar fracture. In order to clarify the anatomy of the fascia iliaca compartment, the diffusion mode, range of the drug solution after injection of local anesthetics, and the clinical effects of FICB, this article reviews the anatomy of FICB and the degree of drug solution diffusion, technical improvements, and clinical effects of FICB. Compared with classic FICB and femoral nerve block, suprainguinal FICB has wider spread range and better effect. In the future, it is still necessary to further study the regularity of drug solution diffusion into the paravertebral space after FICB by different approaches.