The invention belongs to the technical field of bridge monitoring, and particularly relates to a bridge health monitoring system based on a wireless sensor network and a working method thereof. The bridge health monitoring system comprises a processor module, a cloud server and a remote monitoring terminal, wherein the processor module controls sensor modules for detecting a bridge state; the cloud sensor receives bridge state data sent out by a control module through a wireless communication module; and the remote monitoring terminal acquires the bridge state data from the cloud server. The prediction ability for risks is improved, and the bridge health monitoring system is perfected.