Abstract: At present, the layout plan of cable force sensors for cable-stayed bridges usually selects different specifications of cables and cables with large cable forces or significant stress amplitude changes for monitoring, lacking a scientific method of cable force sensor placement. This study proposes an optimal cable force sensor placement method for long cable-stayed bridges based on sensitivity analysis, aiming to identify the structural damage in cable-stayed bridges. The proposed method is based on the sensitivity analysis of cable force to structural damage, and a genetic algorithm is used to obtain the minimum number and placement position of cable force sensors that required to identify structural damage in cable-stayed bridges. In addition, engineering experience and sensor placement habits are fully considered when determining the initial population and constraint condition of genetic algorithm. The proposed method is applied to the numerical model of the Yuxi River Bridge, and the optimal cable force sensor placement for cable-stayed bridges with the target of damage identification is realized. Moreover, the influence of sensitivity threshold on the optimal placement of sensors is discussed.