The invention discloses gliclazide sustained-release tablets, which are prepared by evenly mixing drug-loading particles with pharmaceutically acceptable adjuvant materials and tabletting the obtained mixture; a preparation method of the drug-loading particles comprises the following steps: heating glyceryl behenate up to 65-70 DEG C for melting, then adding meglumine and evenly stirring in a heat preservation process, adding gliclazide and stirring until the mixture is molten, cooling for solidifying, and pelletizing, wherein the mass ratio of the gliclazide to the glyceryl behenate to the meglumine is equal to 1 to (1.5-4.5) to (0.1-0.3). The gliclazide sustained-release tablets are stable in drug release speed, better in drug stability, high in bioavailability, simple in preparation technology and suitable for industrial mass production.