<p>The paper utilizes a combination of entropy production theory and numerical simulation to analyze the energy dissipation of Francis turbines. The distribution law of local entropy production rate (LEPR) in various components of hydraulic turbines is explored under different operating conditions. A detailed examination of hydraulic losses within the Francis turbine reveals that the primary contributors are the runner and draft tube, with comparatively smaller losses occurring in the spiral casing and guide vane areas. The study further explores the formation reasons behind these losses. Within the runner area, the LEPR mainly concentrates in the inlet area of the blade channel, as well as the pressure and suction surfaces of the runner blades. The main reason for hydraulic losses in the runner area is the movement of vortex structures in the blade channel. Within the draft tube area, the hydraulic losses mainly occur on the walls of the straight cone section and the elbow section. There is a backflow phenomenon in the draft tube, which is the main reason for hydraulic losses in the draft tube area. This article can provide a certain theoretical reference for exploring the influencing factors of hydraulic losses in hydraulic turbines.</p>