The invention discloses a block chain transaction network node importance ranking method. The method comprises the steps that A, a transaction network topological graph is generated; B, background nodes are added; C, edges from non-background nodes to the background nodes are added; D, edges from the background nodes to all the non-background nodes are added; E, a probability transfer matrix is generated, and an initial importance score is given to each node; F, power iteration is performed on the probability transfer matrix H; G, whether convergence is performed is judged, if yes, the step His executed, and if not, the step F is returned to and executed; and H, the background nodes are deleted, and the importance scores of the remaining nodes are obtained. By the adoption of the method,the importance ranking result of the block chain transaction network nodes can better conform to the nature of a block chain transaction network, and the fairness and credibility of importance rankings of the block chain transaction network nodes can be improved.