In order to improve the interfacial bonding strength of wheat straw fibers and polypropylene (PP), the wheat straw fibers were treated by combining treatment. The surfaces of fibers were pretreated by five methods, such as NaOH, soaked in acetic acid solution, hydrothermal treatment, steam explosion treatments and microwave treatment. Then, they were compounded with coupling agent treatment. The wheat straw/PP composites were prepared by melt blending and molding. The microstructure of wheat fibers after different surface treatments was observed by stereo microscope. The infrared spectroscopy of wheat straw fibers after different surface treatments was examined by Fourier transform infrared (FTIR) technology. The tribological properties of PP composites filled with different surface treated wheat straw fibers were investigated by using M-2000A abrasion testing machine. The results showed that NaOH, hydrothermal treatment and steam explosion treatments had significant impact on the chemical composition of wheat straw fiber. The tribological properties of PP composites filled with combined treated fibers excelled than that of the composites filled with coupling agent treated fibers. The main wear mechanisms of worn surfaces were abrasive wear and adhesive wear. It was found that the composites filled with hydrothermal treatment and steam explosion treatment had good tribological properties.