A data-transmitting method for wireless sensor network includes: constructing a wireless sensor network having a plurality of nodes for information sensing and a sink for quest raising and data collecting; clustering the nodes to form a plurality of groups, with one of the nodes in each group being identified as a kernel; identifying one of all the nodes as a summit dissemination node and the kernels in all the groups as first level dissemination nodes; and transmitting data between the quest-raising sink and one of the first level dissemination nodes or summit dissemination node to collect information sensed by a source that is one of the nodes.