The invention discloses a trimetazidine dihydrochloride sustained-release tablet and a preparation method thereof. The trimetazidine dihydrochloride sustained-release tablet comprises the following constituents in percentage by mass: 5-60% of trimetazidine dihydrochloride, 10-25% of sustained-release framework material, 1-8% of adhesive, 20-80% of filler, 0.1-5% of glidant and 0.2-3% of lubricant. According to the trimetazidine dihydrochloride sustained-release tablet, medicine can be slowly and uniformly released by adding the sustained-release framework material, so as to achieve regulation and control for a release speed, reduce the peak-valley ratio of the medicine, improve the efficacy, reduce the toxic and side effects of the medicine, reduce daily medicine-taking times and enhance the compliance of the patient on the medicine. The preparation method of the trimetazidine dihydrochloride sustained-release tablet disclosed by the invention is simple in process, does not need specially process production equipment, and is low in cost and good for batch amplification and industrialized production for products.