The invention provides an external fixator applied to transverse fibula movement. The external fixator comprises a ring-shaped external fixator frame body (1), a proximal tibia extension and angle adjustment fixing unit (2), a distal tibia extension and angle adjustment fixing unit (3) and an olive needle fixing rod (4), wherein olive needles can be fixed in threaded holes formed in the middle part of the olive needle fixing rod (4), and the top ends of a proximal fibula olive needle (4-1) and a distal fibula olive needle (4-2) are respectively fixed in the threaded holes by an olive needle fixator (4-3). The external fixator applied to transverse fibula movement has the advantages that the current lack of a clinically effective and mature external fixing frame system for transverse fibula movement is made up; the external fixator is simple in structure, simple and convenient in operation as well as firm and reliable in structure; the external fixator is capable of accurately moving fibulas into a tibia defect area transversely, thus being beneficial to solving the clinical problems such as tibial bone defects and crus soft tissue defects at the same time; therefore, the external fixator is especially suitable for patients with tibial massive bone defects and poor soft tissue coverage of residual healthy tibial tissue muscle.