The work aims to study the properties of the four most common wastepaper fibers and explore the wider use of wastepaper, so as to realize the high value and resource utilization of wastepaper. The morphological and structural characteristics, crystallization and pyrolysis performance of fibers in waste newspaper, cardboard, printing paper and book paper were studied by means of fiber analysis, FT-IR, XRD, SEM and TG. The waste newspaper fibers had rougher surface and were badly damaged and kinked, and the content of fine fiber was high, so the thermal stability was the worst. The roughness of cardboard fibers was higher, and the degree of kinking was the lowest. The length-width ratio of printing paper fibers was the biggest and the morphology and surface were relatively complete. The book paper fibers had large roughness and the maximum crystallinity. Through FT-IR analysis, there were fewer hydroxyl groups on the surface of cardboard fibers, but more fillers on the printing paper and book paper. The fibers of waster cardboard and boob paper have better comprehensive performance and are more suitable to be combined with other materials.