Aiming at the problem of output voltage oscillation and deterioration of power quality caused by parameter changes of Boost cascade converter, an active disturbance rejection suppression strategy that improved coati algorithm is proposed. First, a simplified discrete model of the cascade converter was established to prove the existence of period-doubling bifurcation in system and combined with simulation verification, it was concluded that the low -frequency oscillation of the port output voltage was due to the period-doubling bifurcation disturbance in the system; Secondly, using linear active disturbance rejection controller compensates for disturbance estimation. Since manual tuning of parameters is inefficient and difficult to ensure accuracy, improved coati algorithm is introduced to realize adaptive tuning of controller parameters. In terms of algorithm, SPM chaos mapping is used for initialization to increase population diversity; Incorporating Levy flight and refractive backward learning strategies to avoid the algorithm falling into local optimum and to improve the efficiency and quality of parameter finding. Finally, through simulation verification and analysis, improved coati algorithm parameter configuration is more accurate and efficient, and the tuned controller can effectively suppress period -doubling bifurcation disturbances and improve the quality of transmitted power.