Combining the characteristics of blockchain technology with distributed ledger, consensus mechanism, encryption algorithm, etc., this paper proposes a filtering algorithm based on intangible cultural heritage, builds a video tracking scanning imaging model of dancers in ethnic areas, and detects the edges of video images of dancers in ethnic areas. The contour model is used to enhance the video images of dancers in ethnic areas according to the initial contour distribution, and establish a visual perception model of the dancers in ethnic areas. Sequence, the posture probability of the observation sequence is obtained through the forward-backward algorithm, and the corresponding posture of the hidden Markov model with the largest observation sequence probability value is the dance tossing posture that needs to be recognized.