Binary beetle-swarm (BAS) and its optimization algorithm (BSO) is a new biological heuristic algorithm in recent two years,which is easy to implement and fast in convergence,but it is only suitable for continuous function optimization.At present,there are few researches on the sensor placement optimization in the structural health monitoring system of high piled-wharf,and the placement method is blind.Aiming at the discrete problem of sensor optimal placement of high piled-wharf,this paper adopts the method of “0-1” coding,introduces the idea of position transformation probability,discreting BSO algorithm,and proposes a method of sensor optimal placement of high piled-wharf based on the criterion of modal confidence by BBSO algorithm.Based on the case study of a high piled-wharf,the application of the proposed method is studied and compared with the traditional BPSO algorithm.The results show that the proposed method is more suitable and effective than the traditional BPSO algorithm.