The automatic flow cotrol valve relates to a liquid and gas flow direction and flow automatic control device, and is designed primarily to eliminate the problem of halfway separation of over hot fluid. The automatic flow control valve comprises an inlet casing, an outlet casing and a rubber ring and so on. A concave passage is provided on inner wall of the outlet casing. A guide support is arranged in a chamber and is connected with an external guide plate with rivets. Holes are provided on end face of the external guide plate, outer wall and end face of the guide support. An adjusting nut is provided on the guide support and is provided with a regulating lever. The regulating lever is provided with a sealing cover, a seal ring, a splint, a rubber seal sleeve. Expanding material, a regulating sleeve and a guide sleeve are provided outside the rubber seal sleeve in turn. An internal guide plate is perforated and is fixed with the guide sleeve. Both ends of a spring prop up the internal guide plate and the external guide plate, respectively. The utility model is characterized in thorough control of separation of over hot fluid, safety and reliability.