The invention discloses a tree-node displaying method and a device thereof. The method comprises the steps of setting a double-check box for each tree node, respectively named as a first check box anda second check box, wherein, the first check box indicates whether the node is associated with all descendant nodes thereof or not; the second check box indicates whether the node has associated relationship with superior nodes or indicates the state whether the node is selected or not when the node is not associated with the superior nodes; when tree nodes are displayed, direct subordinate nodesof the selected nodes are displayed by a lazy load way, and whether all subordinate nodes of the selected nodes are associated or not is determinated according to the state of the first check box andthe second check box corresponding to the selected node. By using the invention, tree nodes can be displayed on the basis of lazy load, business display performance is provided, and meanwhile, the association of all descendent nodes is realized.