The invention discloses a high-melt-strength polypropylene material and a preparation method and device thereof. The high-melt-strength polypropylene material is prepared from, by mass, 70-98 parts of polypropylene matrix, 2-30 parts of a fiber forming phase, 1-9 parts of a compatilizer and 0.1-0.5 part of an antioxidant. A polypropylene material, the fiber forming phase, the compatilizer and the antioxidant are added into an extruder in a micro-nano laminating extrusion device to realize extrusion, and by further stretching after extrusion and strong shear action of a multiplier in the polymer micro-nano laminating co-extrusion device, microfibers formed by the fiber forming phase are long and thin and uniformly dispersed in the polypropylene matrix material, and diameters of the microfibers reach the nano level. The long and thin microfibers can be entwisted with polypropylene molecular chains to form a physical network, and accordingly melt strength of the polypropylene material is improved, and foaming performance of the polypropylene material is improved.