The invention relates to matrix diclofenac potassium sustained-release pellet capsules and a production process thereof. The matrix diclofenac potassium sustained-release pellet capsules are prepared by filling matrix diclofenac potassium sustained-release pellets into gastric-soluble capsule shells. The matrix diclofenac potassium sustained-release pellets are prepared in one step by extrusion and rolling. The formula of the matrix diclofenac potassium sustained-release pellets comprises basic remedy diclofenac potassium 10-50%, matrix agent 1-20%, diluent 20-80%, antioxidant 0.1-5%, antisticking agent 0.1-5%, absorption promoting agent 1-10%, and any available wetting agent as balance, wherein the matrix agent is hydrophilic gel matrix agent, or hydrophilic gel matrix agent and erodiblematrix agent, or hydrophilic gel matrix agent and insoluble matrix agent. The matrix diclofenac potassium sustained-release pellet capsules provided by the invention have the advantages of high bioavailability, long in vivo holdup time, regular drug release, good in vivo (Beagle dogs) absorption and reproducibility, good sustained-release effect, simple production process, short production period, and no flying of dust during production, and are suitable for industrial production.