The invention discloses an unknown node positioning method of utilizing multi-hop nodes to reduce a possible position area, mainly comprising: unknown nodes continuously reducing the possible position area of the unknown nodes by utilizing the position relation between the virtual communication circle of anchor neighbors and unknown node neighbors relative to the unknown nodes and the current possible position area of the unknown nodes, and the position relation between the necessary communication circle of the anchor neighbors and unknown node neighbors and the current possible position area of the unknown nodes; the unknown nodes traversing all anchor neighbors, and then traversing all unknown node neighbors; and calculating the centroid of the possible position area of the unknown nodes at the moment to be used as the estimation position of the unknown nodes when the possible position area of the unknown nodes does not change. The method utilizes all multi-hop nodes in a network to eliminate the possible position area of the unknown nodes, effectively improves positioning precision, has small computational complexity based on convex polygon operation, and can effectively reduce node and network energy consumption, and prolong the service life of the network.