Due to the non-linear and strong coupling characteristics of the marine steam power system, and the requirement of security and economy, boiler-turbine system coordination control is very necessary. The model of power system is identified by the diagonal recurrent network, with parameters of PI controller online self-tuned by Jacobian information, so multivariable decoupling control of boiler-turbine coordination is realized. The process simulations show that the system can achieve a good tracking performance of the drum pressure and output power over a wide operating range, while the water level in the drum is kept within tolerance, and it has a strong anti-interference ability.