Abstract: Active-passive isolation is an important technology to control low-frequency sinusoids of ship noise, but it has been rarely applied in engineering practice. Based on principle research of isolation system using electromagnetic actuator and air spring, engineering actuators are designed with advantages of small volume, large output force, low power consumption, etc. Active-passive isolators are also developed with good stability and good adaptability to shock and swing in ship environment. To achieve highly efficient control in circumstances of multiple sinusoids, MIMO coupling and amplitude fluctuation, engineering algorithms are developed: the system is linearized by compensation with a nonlinear inverse model, and a time-domain Fx-Newton narrowband algorithm is proposed to ensure rapid and stable convergence. The active-passive isolation system is mounted under a 200 kW ship diesel generator and experiment results show that this system has excellent isolation effect on broadband and low-frequency sinusoidal vibration, with satisfactory performance for engineering application.