The invention relates to a preparation process of sodium bicarbonate Ringer's injection and an intermediate quality control method thereof. Since the preparation formula simultaneously contains Ca<2+>and HCO<3->, CO3<2-> is easily produced from the HCO<3-> in the preparation process, and the CO3<2-> is further reacted with the Ca<2+> to easily produce a precipitate CaCO3, the formula is always atechnical problem of industrial production of the product for a long time. According to the technical scheme provided by the invention, the solution is prepared by a dilute preparation method, the initial addition amount and dosing sequence of water for injection before feeding sodium bicarbonate and the pH value and content of the preparation intermediate are controlled, and industrialized production of the sodium bicarbonate Ringer's injection can be effectively realized. The preparation process involved in the technical scheme is simple, convenient and feasible; and the intermediate qualitycontrol method contributes to ensuring stable and controllable quality of the finished injection, and the clinical medication safety is ensured. The invention belongs to the field of biological medicine.