1. A method for generating a tree map, the method comprising: obtaining, with a processing device, node information of a plurality of nodes to be processed, the plurality of nodes to be processed being sub-nodes sharing a same parent node and the node information comprising at least sizes of the nodes; determining from the plurality of nodes a plurality of candidate nodes whose sizes are less than a threshold size; determining at least one super node including the plurality of candidate nodes based on the node information of the determined plurality of candidate nodes, a screen size, and the threshold size, such that when displaying in a zooming-in mode the super node on the screen, all candidate nodes in the super node are displayed at display sizes not less than the threshold size; and determining data required for displaying the tree map based on the determined super node.