Abstract: Helicopter cabin noise negatively impacts cabin environmental comfort and safety. In this paper， non-dominated sorting genetic algorithm Ⅱ is used to solve the electro-acoustic device placement problem of the active control system applied in the cabin. An appropriate spatial discretization of the sound field of the confined space is preformed， and then the electro-acoustic devices placement optimization problem， quantity optimization problem， and secondary source sound intensity optimization problem are further transformed into a combinatorial optimization problem. Taking the minimun value of the sum of the squares of the acoustic pressures at the measurement points as the control objective， the multi-objective optimization algorithm combined with the active control algorithm is adopted to solve the optimal placement of electroacoustic devices in the system. Considering the noise control system’s complexity and feasibility and limited space inside the cabin， the control system’s secondary sound sources and error sensors are selected as a 4-channel configuration. The optimization program is repeated several times independently， and the most frequently occurring positions of electroacoustic devices are counted， based on which computer simulation and experiment are conducted， and the results show that the optimization results can make the noise reduction at the height of the head of the cabin personnel in the sitting position reach up to 24.9 dB， and the global noise reduction reaches 19.4 dB.