The invention discloses an oxiracetam composition with dehydrating and urination promoting effects and application thereof. The composition is mainly prepared from the following 1,000mL of raw materials in total: 160-200g of oxiracetam, 8.5-9.5g of sodium chloride, and the balance of water for injection. The composition can take effects of dehydrating and promoting urination quickly, has a long-lasting action of reducing intracranial pressure, is convenient to use, can pass through blood-brain barrier, but not enter brain cells, thereby avoiding increase of intracranial pressure. The composition is convenient in administration, does not crystallize at room temperature, and is suitable for sudden-onset disasters at ordinary times and cold regions, low temperature, wild field and other harsh environments in wartime. The composition can be rapidly discharged via kidneys to generate good urination promoting effect, has no renal function damage and other side effects, and has good water solubility, high solubility, no toxicity, high safety and no tolerance or accumulated side effects after repeated administration. The composition can be used for emergency and severe disease rescue, improving brain metabolism, promoting consciousness, and accelerating recovery of cognition and limb function after injuries, and has multiple-effect characteristic.