The invention discloses a florfenicol premixing agent. The florfenicol premixing agent is prepared from the following raw materials in parts by weight: 2 to 3 parts of florfenicol bulk drugs, 2 to 15parts of active auxiliary materials, 2 to 10 parts of carriers, 10 to 25 parts of dissolution agent, 2 to 10 parts of stabilizer, and the balance of filling agent. The obtained florfenicol premixing agent has the advantages of high biological activity, high bioavailability, high stability, low cost, small toxicity and side effect, multiple effects and capability of promoting the growth of animals.By adopting the preparation method of the invention, the defects of a conventional complicated solid inclusion process can be avoided, the use of expensive reagent can be avoided, the process flow issimple, the cost is simple, and the preparation method has positive popularization significance.