In malicious environment

some anchor nodes may be occupied by attackers

and then sent incorrect informations over the network

intending to prevent precise positioning of the other nodes.Various of attack types existing in wireless sensor networks（ WSNs） is introduced

mathematical model of coordinated attack is established

and a secure localization algorithm to defend against coordinated attack is proposed.Simulation results show that the algorithm is still able to accurately locate the node even in the case of a larger attack strength in coordinated attack environment by 30 % malicious nodes

and the average localization error is not more than 2 m.