Abstract: By analyzing the misjudgment cases of field metallographic examination, the causes that may lead to the misjudgment of field metallographic examination were summarized, some improvement measures were put forward, and finally the factors that must be considered were summed up to prevent the misjudgment of field metallographic examination. It is suggested that when conducting field metallographic inspection and microstructure judgment, inspectors should comprehensively consider the surface condition, wall thickness, environment, field equipment capacity and other factors of the tested material, so as to prevent the deviation of microstructure judgment and technical risk caused by neglecting these factors.