The invention discloses a method for preparing a continuous glass fiber reinforced polypropylene unidirectional prepreg tape, comprising: 1) uniformly mixing polypropylene, a polypropylene-based ionomer and an antioxidant, heating and melting to obtain a melt mixture; 2) The continuous glass fiber is drawn out from the creel, flattened, and then enters the corona charging device, so that the continuous glass fiber is charged with the opposite charge to the polymer chain of the polypropylene-based ionomer; 3) after being treated in step 2) The continuous glass fiber is coated with melt mixture, kneaded and impregnated, calendered and impregnated, cooled and shaped, and rolled. The invention also discloses the continuous glass fiber reinforced polypropylene unidirectional prepreg tape prepared by the method. The product prepared by the invention has the characteristics of sufficient impregnation of polypropylene to continuous glass fiber, low porosity, good interface bonding, excellent mechanical properties, and no release of small molecule volatiles during subsequent processing and use, and can be used for continuous fiber reinforced polypropylene Sheet, plate and special-shaped structural parts and other fields.