The working principle and working conditions of the hydraulic braking system of a mine dumping truck from a company were introduced.Type faults of the hydraulic braking system,including inadequate brakng,brakes did not release and emergency brakes failure,were analyzed.Fault remedy measures that checking system pressure,leakage and solenoid etc were discussed detailedly in the factual work.It provides reference for fault analysis and remedy of hydraulic braking system of mine dumping trucks.