Clinically, abdominal aortic aneurysm (AAA) may continue to expand or even rupture after endovascular aneurysm repair (EVAR) due to endoleak or endotension. The existence of endoleak and endotension can significantly affect the mechanical/hemodynamic environment in AAAs, thus changing the strain and stresses on aneurysm wall, further influencing the transportation of low density lipoprotein (LDL), oxygen and nitric oxide (NO) in AAAs and aneurysm wall, which might eventually alter the biochemical environment and physiological property of aneurysm wall. This review focused on biomechanical mechanism of AAA enlargement after EVAR and its recent research progress, which indicated that reduction of the aneurysm wall strength due to deterioration of biomechanical environment (such as increase of tensile stress on aneurysm wall) and abnormity of biochemical environment (such as increase of LDL deposition, change of oxygen concentration) might be the source leading to AAA enlargement after EVAR. Based on previous studies, the authors propose that comprehensive investigations on AAA enlargement after EVAR from the perspective of biomechanics and mechanobiology have great research values and clinical significance, which will help clarify the mechanism of AAA enlargement after EVAR, as well as optimize the strategies of aneurysm repair surgery and designs of interventional medical devices.