Abstract: When an engine turbine blade was disassembled and inspected, it was found that there were abnormal convex features such as linear ridges, bulges and folds on the blade surface. The causes for aluminum-silicon coating bulge on the blade surface were analyzed by means of macroscopic test, metallographic examination, scanning electron microscopy and energy spectrum analysis, and simulation test. The results show that the blade has experienced high temperature conditions of 1 100~1 150 ℃. Under the combined action of working stress and high temperature, the Al-Si coating on the blade surface softened. During the high-speed rotation of the blade, the softened coating structure on the surface flowed, and finally formed abnormal protrusions such as linear ridges, bulges and folds on the blade surface.