Abstract: Damage identification based on multi-type sensor data integration have been received more attention in structural health monitoring field. Furthermore, the effect of damage diagnosis based on multi-type sensor data integration depends on the optimal sensor placement for multi-type sensor data integration. Therefore, in the paper, an innovative optimal sensor placement based on sensitivity is proposed for damage identification to determine the number and locations of three kinds of sensors including accelerometers, Fiber Brag Gauges (FBG), and piezoelectric (PZT) sensors on plate-like structure monitoring. With considering the boundary effect and uncertainty caused by environment, the sensitivity-based object function is established to evaluate minimum sensor number of accelerometers, FBG and PZT, respectively, for the equivalent identification solution. Then the optimal locations and number for three kinds of sensors are calculated. Finally, simulations of fixed-supported steel thin plate-like structure are performed to illustrate the effectiveness of optimal sensor placement.