The invention discloses a natural latex rubber fresh-keeping enzyme and a method for concentrating natural latex rubber by using the natural latex rubber fresh-keeping enzyme. The natural latex rubber fresh-keeping enzyme comprises, by weight, dry rubber tree leaves, microzymes and tea leaves. A preparation method of the natural latex rubber fresh-keeping enzyme comprises the following steps: preparing a rubber tree leaf starter, preparing a tea polyphenol regulator, and mixing the rubber tree leaf starter with the regulator. The method for concentrating the natural latex rubber by using the natural latex rubber fresh-keeping enzyme comprises the following steps: adding water to dilute the natural latex rubber, filtering the diluted natural latex rubber, and carrying out concentration separation by using a high speed centrifuge. The method can inhibit denaturation of proteins, and the natural latex rubber fresh-keeping enzyme can completely substitute ammonia water with a fresh-keeping function, can keep the fresh scent of the natural latex rubber for a long term without adding any chemical antiseptics when being applied to concentration of the natural latex rubber, and is a pure-natural, green, nuisance-free and pollution-free natural latex rubber fresh-keeping enzyme. The natural latex rubber fresh-keeping enzyme generates no unpleasant smell, has a better fresh-keeping effect than the ammonia water, and also has the advantages of good compatibility with other assistants, low cost, simplicity and convenience in use, and no pollution.