The invention discloses a maritime search and rescue wireless sensing network synergic positioning method which comprises the following steps: S1, establishing a Lagrange model as a marine movement model of a node; S2, acquiring a synergic positioning system model of an unknown node on the basis of an unknown node state model described by an invisible markoff chain and a marine movement model and an observation model of the node, estimating posterior probability distribution by using a particle filter algorithm, and estimating the position of the unknown node according to the estimated posterior probability distribution; S3, improving a likelihood function in the particle filtering algorithm by using KL (Kullback Leibler) divergence, and reducing errors caused by sea wave shielding factors by optimizing parameters; and S4, introducing the likelihood function of the optimized parameters, updating confidence factors and iterative position estimation in a residual error-system resampling mode to alleviate degeneration of particles, and estimating the position of the unknown node. The method has the advantage that positioning errors caused by marine shielding effects and multipath effects on an offshore wireless sensing network are avoided.