The invention discloses low-odor high-transparency ultrahigh flowability polypropylene which comprises the following components in percentage by mass: 96-99.89% of a polypropylene resin, 0.1-2% of a free radical form initiator, 0-0.2% of a lubricant, 0.01-0.3% of an antioxidant and 0-1.5% of a compounded transparent nucleating agent. Due to adoption of the compounded transparent nucleating agent which is sufficiently reacted with the polypropylene resin, the initiator, the lubricant and the antioxidant synergistically, the ultrahigh flowability polypropylene which is high in transparency, lowin yellow index and low in haze is prepared. In addition, the invention further discloses a completely novel preparation device and process of the low-odor high-transparency ultrahigh flowability polypropylene. The transparency, the low odor and the low volatilization of the product in the preparation process can be further improved on the basis of a completely novel formula, the product can be prepared by using a one-step method, large-scale popularization and production in factories can be implemented, meanwhile, the problem of small molecule residues in the product is also solved to a largeextent, and aftertreatment processes of non-woven fabric manufacturing companies can be simplified.