The invention discloses an Empagliflozin oral solution and a preparation method thereof. The Empagliflozin oral solution is prepared from Empagliflozin and pharmaceutical excipients. The medicinal excipients comprise a pH regulator, a solubilizer, a flavoring agent, a bacteriostatic agent and water. The preparation method of the Empagliflozin oral solution includes the following steps: 1, adding the other components except the pH regulator into 80% of the prescription dosage of purified water, stirring and dissolving; 2. adding the pH regulator into the solution obtained in the Step1and makingthe pH value to be 6.0-8.0; and 3. adding purified water to the prescription dosage, keeping the pH value of the solution at 6.0-8.0, and filtering through a 0.8 um filter membrane so as to obtain the Empagliflozin oral solution. It is finally found through a large number of experiments that the Empagliflozin oral solution within a certain pH range of 6.0-8.0 has good stability. Thereby, the problem that existing Empagliflozin tablets have poor compliance can be improved, and especially a more convenient administration method is provided for Type 2 diabetes patients with swallowing dysfunction.