The phenomena of pipeline ice-blocking occurs from time to time in cold regions.Distributed fiber-optic sensor is used to detect the information of ice-blocking occurred along the pipeline.The method of wavelet analysis which has the capacity of local signal characteristics is used to determine the time delay of two test signals at both ends of the optical fiber.Then the location of the point of ice blocking can be determined.The testing principle and the method of plugging point positioning is described.Theoretical analysis and simulation results shows that this method can effectively improve the sensitivity and positioning precision of pipeline ice-blocking test.