Aiming at the crack phenomenon in a hydraulic turbine runner blade, from the perspective of the influence of the start-up law of the turbine governor on the runner, an electro-hydraulic servo system model considering nonlinear parts and a hydraulic turbine model based on comprehensive characteristic curves were established. The closed-loop start-up characteristics for hydraulic turbines whose rising curve of the expected rotation speed shows a straight line rule were analyzed. Considering the deviation of working head and other factors, a comprehensive index is proposed. The start-up process of a Francis hydraulic turbine in China was simulated. The results show that the closed-loop start-up process based on the comprehensive index can obtain a strong dynamic performance and reduce the impacts of the start-up laws on the runner.