The invention discloses a long glass fiber enhanced polypropylene composite material with low shrinkage and low warpage, a preparation method thereof, and application of the long glass fiber enhanced polypropylene composite material in manufacturing an automobile tail door sheet. The composite material is prepared from the following raw materials in parts by weight: 30-80% of polypropylene, 10-60% of continuous glass fiber, 3-10% of compatilizer, 0.1-1.5% of antioxidant, 0.1-1% of lubricating agent, 0.5-3% of coupling reagent, 0.1-2% of nucleating agent, 5-20% of zinc oxide whisker and 0.5-3% of glass bead. The zinc oxide whisker, the nucleating agent and the glass bead are compounded, so that the composite material achieves an ideal enhancement effect, the differential degree of glass fiber along a fiber glass orientation between a flowing direction and a vertical flowing direction in a polypropylene matrix is reduced, and the shrinking percentage and the warping degree of the composite material can be obviously lowered. The long glass fiber enhanced polypropylene composite material can be used for manufacturing the automobile tail door sheet.