The invention provides a hydraulic circuit system for a horizontal roller mill with a pressure relief protection function. The hydraulic circuit system comprises a high-pressure oil pump, an electromagnetic relief valve, two hydraulic control check valves, a pressure transmitter, a power accumulator, and a double-acting hydraulic oil cylinder. The high-pressure oil pump is connected with hydraulic control check valves (I) and (II) via the electromagnetic relief valve and an electromagnetic directional valve, and the hydraulic control check valve (I) is connected with a pole cavity of the double-acting hydraulic oil cylinder after passing though the pressure transmitter, a diverting and throttling valve and the power accumulator; the hydraulic control check valve (II) is connected with a pole-free cavity of the double-acting hydraulic oil cylinder; two piston rods of the double-acting hydraulic oil cylinder are respectively connected with the two ends of a press roller of the horizontal roller mill; and an electromagnetic ball valve is connected between the pressure transmitter and the diverting and throttling valve, and a prefill valve connected with the electromagnetic ball valveis connected between the hydraulic control check valve (II) and the pole-free cavity of the double-acting hydraulic oil cylinder. The inventive hydraulic circuit system has reasonable design, minimizes the counter pressure of the hydraulic circuit system, and has good pressure relief protection function, so as to ensure the safe operation of the hydraulic circuit system and effectively improve the milling efficiency and operational reliability of the horizontal roller mill.