Concerning the poor performance in anti-noise and the limitations of the fixed partition of the phase-grouping method, an adaptive phase partitioning method was proposed. Firstly, this paper used the adaptive smoothing and Wallis filtering for image pre-processing and adopted the Canny method for edge detection; secondly, selected the optimal partitioning of the image based on the adaptive phase partitioning method to create the line supporting area; finally, fitted and merged the lines by the least squares method. The experimental results show that the proposed method can effectively solve the line breakage and mistaken extraction caused by the noise and fixed partition, and this method extracts line completely and precisely.