The embodiment of the invention provides a method for estimating non-integral-multiple multi-path time delay. The method comprises the following steps: after a channel impulse response is acquired, determining a position m at which chromatic dispersion occurs when a plurality of paths with chromatic dispersion exist in a channel; determining a path with maximum energy in the chromatic dispersion paths; using the path with the maximum energy in the chromatic dispersion paths as a first center, setting a matching window according to a chromatic dispersion range, and acquiring a measuring sample point set; using time delay corresponding to the path with the maximum energy in the chromatic dispersion paths as a second center, and using a predetermined number of sampling periods T before the second center and a predetermined number of sampling periods T after the second center as a time delay traversing range; performing traversing in the time delay traversing range by taking predetermined accuracy as a step; acquiring a group of local sampling point set through a sinc function according to the matching window and a traversing time delay point; performing correlation matching according to the measuring sample point set and the local sampling point set, and acquiring a traversing step number k when a normalized correlation peak value is maximum after traversing is finished; and calculating multi-path time delay tau of the paths with the chromatic dispersion according to the position m, the traversing step number k and the sampling periods T.