The invention discloses automatic plate blank continuous casting machine tundish pouring method and an automatic pouring system. The pouring method comprises the following steps of: a) opening a water gap of a tundish, and pouring molten steel in the tundish into a crystallizer; b) after the water gap of the tundish is opened for certain time, leading a vortex flow transducer to automatically move to a work station from a waiting station so as to detect height of the molten steel level in the crystallizer by utilizing an automatic escape device; and c) when the vortex flow transducer detects that the molten steel level in the crystallizer reaches a set height, starting a withdrawl and straightening machine and promoting the casting speed to a target set value according to the process requirement. The automatic plate blank continuous casting machine tundish pouring method and the automatic pouring system can solve the problem that the plate blank continuous casting machine of the existing vortex flow molten steel level detector can not realize automatic pouring, reduce the risk on pouring breakout, improve the pouring success rate, and saving the cost.