Locating and detecting algorithm for chip is important in visual detection of electronic manufacturing process. Its performance directly affects the speed and accuracy of assembling chip on Printed Circuit Board. This paper analyzed the common algorithms' disadvantages in locating accuracy. Then based on the above analysis, a new algorithm was proposed, in which B-spline is used to detect edge accurately and help to mount chip more precisely. Experiment results demonstrated that the proposed algorithm's performance is better than SUSAN and Canny algorithms' in locating accuracy and stability, and can meet the practical demand of mounting chip.