Self-circulation evaporative cooling system of stator collector ring of hydro-generator is a new cooling system, with advantage of high-security, energy-saving and high efficiency. In this paper, the loop resistance in single stator collector of hydro-generator was analyzed deeply and detailedly, by experiment and simulation. The simulation method of system resistance was introduced. The comparing results between experimental data and simulation results show that the prediction precision of pressure distribution of coolant in system is satisfying and the simulation method is reliable and can be utilized in application engineering field.