1. An ophthalmic gel containing a therapeutically effective amount of gatifloxacin or its pharmaceutically acceptable salts, a matrix and water, where the matrix is one or more selected from the group of carbomer, a mixture of carbomer and hydroxypropyl methylcellulose, and sodium hyaluronate. 2. An ophthalmic gel that contains a therapeutically effective amount of gatifloxacin or its pharmaceutically acceptable salts, carbomer, sodium hyaluronate and water. 3. Ophthalmic gel according to claim 2 in a percentage ratio of the mass / volume of the gel, includes: 4. The ophthalmic gel according to claim 2 in a percentage ratio of the mass / volume of the gel includes: 5. The ophthalmic gel according to claim 2 in a percentage ratio of the mass / volume of the gel includes: 6. The ophthalmic gel according to claim 2 in a percentage ratio of the mass / volume of the gel includes: 7. The ophthalmic gel according to claim 2 in a percentage ratio of the mass / volume of the gel includes: 8. The ophthalmic gel according to claim 1, wherein the gel further comprises a pH adjuster, and the pH adjuster may be selected from one or more of the group consisting of boric acid, borax, sodium hydroxide, phosphate buffered solution and acetate buffered solution； in particular, the pH of the ophthalmic gel is 4.5-9.5.9. The ophthalmic gel according to claim 1, wherein the gel further comprises an osmotic regulator, and the osmotic regulator is selected from one or more of the group consisting of propylene glycol, glycerin, sodium chloride and mannitol, in particular, the ophthalmic gel contains 0-15.0% (mass / volume) of the osmotic regulator. 10. The ophthalmic gel according to claim 1, wherein the gel further comprises one or more bacteriostatic1. Офтальмологический гель, содержащий терапевтически эффективное количество гатифлоксацина или его фармацевтически приемлемых солей, матрицу и воду, где матрица представляет собой один или несколько, выбранных из группы карбомера, смеси карбо
