The invention discloses a plant fiber reinforced composite material. The composite material comprises the following components, in percentages by mass: 70%-90% of a red earth containing waste mulch film, 5%-25% of plant fiber scraps, 1%-5% of a coupling agent, and 1%-5% of a plasticizer. The composite material can be prepared by the steps of firstly preparing composite material particles by adopting an extrusion process, and performing molding to obtain the product by adopting manners such as injection molding and compression molding. According to the composite material provided by the invention, a low-cost simple-process technology is provided for recycling of waste plastics and plant fibers.