The invention discloses a wireless sensor task distribution method based on a contract network. The wireless sensor task distribution method comprises the steps of: S101, clustering common nodes in the network, wherein the common nodes are classified into high-level nodes and low-level nodes; S102, generating a task by a task release node and performing a bidding process between the task release node and the high-level nodes; S103, releasing a bid inviting letter to the managed low-level nodes managed by the high-level node winning the bid; S104, judging whether the low-level nodes are in accordance with a requirement by the low-level nodes per se, determining whether to submit a tender according to the self conditions of the low-level nodes, if determining to submit the tender, turning to S105, or else, dropping out of the tender submission; S105, when the low-level nodes submit the tender, predicting conditions during bid winning and writing the conditions into biding documents; S106, judging whether a bid submission time limit is exceeded or not by the high-level node, if not, continuing receiving tender books, and if so, stopping the receiving of the tender books; and S107, selecting the proper low-level node by the high-level node, and granting the bidding document to the selected low-level node so as to complete a binding process. According to the invention, the energy consumption of the network and communication conflicts can be reduced, and the task completion rate and the completion quality can be increased.