Based on the internal wall erosion testing equipment used in the gasif ier refractory brick measurement, the point cloud data were acquired and process further. With the way of screening and rejecting, noise smoothing and refinemen t of the data was realized. Threedimensional model of the internal wall erosio n condition was built by using the point cloud aligning, grid plotting and displa ying with different colors. This study focused on the methods of preprocessing and postprocessing of the point cloud data. According to threshold value of th e firebrick erosion, an approach to identification and segmentation for the erode d region of the wall of gasifier was presented. The firebrick erosion analysis p rovides a dependable guidance for manufacture and maintenance of gasifiers.