As the main water-retaining structure of hydraulic engineering, steel gate in service being impacted by surrounding environment and operation load, will be damaged by coating desquamation, steel plate rusting, attrition, distortion, and so on. It’s important to detect and identify the safety of steel gate. Based on the advanced instruments and data processing, Xukou sluice is simulated and calculated with 3D FEM software to re-check its stiffness and strength. The safety appraisal shows the steel gate of Xukou sluice meets the standard of the current engineering specification.