The invention discloses a pulse noise detection method of a power line communication channel, comprising the following steps of: S1, sampling noise of the power line communication channel; S2, segmenting continuous sampling points; S3, computing the average value of absolute values of all segments; S4, computing the average ratio of absolute variances of all the segments; S5, computing the average value of average ratios of the absolute variances; S6, comparing the average ratio of the absolute variances with the average value; if the average value of the absolute variances of a segment is larger than the average value, turning to step S7; otherwise, turning to step S8; S7, judging whether noise data amplitude in the segment exceeds a preset noise threshold; if so, judging that the segment appears the pulse noise once; otherwise, judging that the segment has no pulse noise; judging whether the comparison is over; if so, returning results; otherwise, turning to the step S6 and continuing to compare. Recognition accuracy of pulse noise is improved by using the method.