Wireless sensor networks( WSNs) health evaluation is an important measure to ensure normal running of WSNs and prolong its life. A WSNs health evaluation method based on fuzzy AHP is proposed. Single and comprehensive weight of every evaluation index are obtained on the basis of the evaluation hierarchical structure model and fuzzy complementary judgment matrix
and the WSNs health evaluation index
health degree is given. Experimental result shows this method can quantitatively and properly evaluate the WSNs health status.