Abstract: The present invention relates to a reagent for exploiting natural gas hydrates, which includes a regent A and a regent B. The reagent A is PEG400-polyurethane prepolymer; the reagent B includes PEG400 and an initiator; and a volume ratio of the PEG400-polyurethane prepolymer, the PEG400 and the initiator is (1-3000):(1-1000):(1-2000). The reagent of the present invention has excellent performance and high stability, and can effectively “replace” the “water” of the natural gas hydrate; and moreover, the reaction is exothermic reaction to effectively increase the reaction rate, which reduces the energy loss on the one hand, and reduces the blockage of a gas passage caused by the secondary generation of the natural gas hydrates in a low-temperature high-pressure pipeline during transferring on the other hand.