An embodiment of the invention discloses a punctuating method and device in pulse wave extraction. The punctuating method includes the steps: detecting each pulse wave signal; filtering high-frequency noise and low-frequency noise of the pulse wave signals, and smoothly filtering the filtered pulse wave signals; acquiring an optimal punctuation of the pulse wave according to a centroid formula and the smoothly filtered pulse wave signals. Low-frequency interference such as baseline drift and breathing ups and downs and interference caused by the high-frequency noise are decreased, and more accurate pulse wave transmission time is computed.