The present invention provides a buffer region generation algorithm method based on line segment buffer region fusion. The method comprises the following steps of: splitting an axis into a plurality of line segments according to positions of turning points; respectively carrying out buffer region calculation on each line segment; and fusing a plurality of buffer regions into a buffer region by using a line segment buffer region fusion algorithm. According to the method, firstly, a multiple line segment boundary of a geographical entity object is broken into a line segments set, then single buffer regions of the line segments are generated sequentially, and finally, the single buffer regions are combined to obtain a buffer region of a geographical entity, so that errors of unequal widths, sharp corners, distortion and the like caused by traditional buffer region generation are avoided; and the finally generated buffer region can really reflect the range of influence, which is more beneficial for simply and intuitively carrying out subsequent space analysis.