The dead zone and limiting of a hydraulic turbine governor have a great influence on the characteristics of the ultra-low frequency oscillations (ULFOs), which can even lead to the oscillation of the positive damping system under large disturbance. However, the existing control methods for ULFOs mainly focus on optimizing proportional?integral?derivative (PID) control parameters of hydraulic turbine governors to improve system damping, without considering the dead zone and limiting parameters concurrently. This paper proposes a ULFO control method considering the dead zone and limiting optimization of the turbine governor and verifies its effectiveness and superiority. Firstly, in a non-smooth single hydro-generator power system (SHPS) with dead zone and limiting, the causes of continuous oscillation with constant amplitude involving dead zone and limiting are analyzed, and the influence of relevant parameters is analyzed, obtaining the qualitative demand for control parameter optimization. Then, a comprehensive evaluation index including the suppression effect of the non-smooth part, the amplification effect of the smooth part, and the performance of the primary frequency regulation is established. Additionally, the optimization parameters are solved using a particle swarm optimization algorithm, and a specific application case of the proposed method is presented. Finally, the proposed method is compared with the control method that does not consider dead zone and limiting optimization, in three simulation systems: SHPS, a four-machine two-area system, and a large-scale power grid model. The proposed method shows improved performance in primary frequency regulation and resistance to disturbance.