Abstract: For ICT image sequence, two kinds of subvoxel surface detection algorithms: facet model-based method and moment-based method are studied. To solve the problem of large computation of both algorithms, a pre-processing procedure based on Otsu threshold segmentation is proposed, which can reduce the number of surface voxel candidates a lot and accelerate the original one greatly. Finally, we compare the two subvoxel edge detection algorithms in the experiment on aeroengine blade simulation data. The results show that both methods can achieve less than 1/5th pixel accuracy and the introduction of the pre-processing procedure can increase the speed about 4 times.