The invention provides a fabrication method for an oriented fibrilia/plastic composite sheet material, which belongs to the field of composite sheet materials. The invention aims to overcome the technical problems that a fibrilia/plastic composite sheet material prepared by using the conventional process of pressure sintering has poor mechanical strength and direction control capacity and a poor creep property caused by bending of fibrilia. The method comprises the following steps: 1, splitting noil fibers or waste gunny cloth into flaxen threads; 2, slightly entwisting polyethylene continuous fibers or polypropylene continuous fibers and the flaxen threads into strands so as to obtain mixed threads; 3, designing a steel frame according to the shape of the oriented fibrilia/plastic composite sheet material, uniformly winding the mixed threads around the steel frame along horizontal and longitudinal directions, putting the steel frame on a backing plate, removing the steel frame, covering an upper platen and placing a cushion block between the backing plate and the upper platen; 4, carrying out preheating; 5, carrying out hot pressing so as to obtain the oriented fibrilia/plastic composite sheet material. The sheet material provided in the invention has the advantages of uniform mixing and firm bonding of fibrilia and polymer, a great breadth, capacity of secondary bending formation, convenient processing, a simple manufacturing process, strong desighnability of longitudinal and horizontal strength, etc.