The invention discloses a high-flow conical-surface stop valve. The high-flow conical-surface stop valve comprises a valve body, a valve rod, a valve sleeve, a threaded sleeve, a hand wheel, a valve rod sleeve and a dust cover, wherein the valve sleeve is arranged in the valve body and arranged on the valve rod in a sleeving mode, the threaded sleeve is connected with the valve body and arranged on the valve rod in a sleeving mode, the hand wheel is connected with the valve rod, the valve rod sleeve is arranged in the threaded sleeve and arranged on the valve rod in a sleeving mode, and the dust cover is arranged on the threaded sleeve and arranged on the hand wheel in a sleeving mode; a first balancing cavity used for allowing liquid to enter is formed between the valve sleeve and the valve rod; a second balancing cavity used for allowing the liquid to enter is formed between the threaded sleeve and the valve rod sleeve; and the valve rod is provided with a damping channel used for allowing the liquid to enter and enabling the first balancing cavity and the second balancing cavity to communicate with each other. According to the high-flow conical-surface stop valve, the first balancing cavity and the second balancing cavity are arranged, therefore, the hand wheel twisting resistance in the opening or closing process is greatly reduced, the operating torque can be reduced, andoperation is easy; meanwhile, the dust cover is arranged, therefore, the complex working conditions under a mine are isolated, and the risk that the hand wheel is corroded due to the fact that the hand wheel is exposed to the poor working conditions to be contaminated is prevented.