Pidotimod injection and its preparation method

The invention provides a pidotimod injection and a preparation method thereof. The pidotimod injection is composed of pidotimod, a pH conditioning agent, and injection water, wherein the pH conditioning agent is sodium hydroxide and one or two of disodium phosphate, sodium dihydrogen phosphate, sodium carbonate and sodium citrate. It is surprisingly discovered that by using the appropriate and specific composite pH conditioning agent, the prepared pidotimod injection keeps stable pH value before and after a solution is sterilized and reduces generation of impurities, and also the injection does not need to use other stabilizers or auxiliary agents. The prepared pidotimod injection is stable and has good pharmaceutical effect, the preparation and the production technology are green and environment-friendly, and the preparation is suitable for industrialized production.