With the wide application of extruded magnesium alloys, how to improve its poor corrosion resistance has naturally become an important research topic inevitably. Through comprehensive analysis on relevant research results in the field of corrosion research of extruded magnesium alloys at home and abroad, the corrosion behavior and protection technology have been discussed. Extrusion magnesium alloy is easy to be damaged by many kinds of corrosion forms, and its corrosion behavior, performance and mechanism are affected by many factors such as material characteristics and corrosion environment, showing diversity and complexity. In particular, the failure behavior of extruded magnesium alloy under the synergistic effect of stress and corrosion needs to be further studied. The microstructure and composition were optimized by optimizing the preparation parameters, alloying and heat treatment. Based on the stress condition and different corrosion environment, the development of a new type of corrosion-resistant extruded magnesium alloy is of practical value for improving the corrosion resistance of extruded magnesium alloy and expanding its application field. Electrochemistry plating, chemical conversion coating, self-healing coating and other coating technologies provide effective protection against extruded magnesium alloy by forming passivation film, ceramic film and releasing corrosion inhibitor on the surface of the alloy. Among them, the self-healing coating can effectively solve the local corrosion problem caused by the damage of the coating, greatly improve the protective performance of the film layer and is a new direction of coating research and development due to good application prospect.