The invention relates to a centre blowing cooling solidification process method for preparing polyvinyl alcohol fiber. The method has the characteristics that the centre blowing cooling technique to cool a polyvinyl alcohol melt extruded from a spinneret plate in a melt spinning is adopted; by controlling various centre blowing process parameters, the centre blowing wind speed is 0.8 to 4m/s, the air temperature is 20 to 25 degrees centigrade, the humidity is 40 to 65%, and the centre blowing height is 0.3 to 1.5m, therefore, the cooling efficiency of a filament tow is effectively improved, the spun raw filament is uniformly cooled, the stability of spinning is improved, the spinning flaw is lowered and the uniformity of spun fiber section is improved, and the water content of spun fibers can be controlled effectively, so that high stretching is realized to manufacture high-performance polyvinyl alcohol fiber which has uniform strength and fineness and high modulus and is suitable for being used as the reinforcing material in concrete.