The invention discloses a feeding mechanism of a cutting machine. The feeding mechanism comprises a working table, a cutting machine head, a rectangular hollow, supporting rods, a feeding plate and hydraulic cylinders, the rectangular hollow is formed in the middle of the working table, the cutting machine head is fixedly arranged at one end of the upper portion of the working table, sliding grooves are formed in the two sides of the part, in the rectangular hollow, of the working table, connecting rods are fixedly arranged on the two sides of the feeding plate respectively, the other ends of the connecting rods extend into the inner sides of the sliding grooves respectively, sliding blocks are fixedly arranged at the ends of the connecting rods, telescopic shafts of hydraulic cylinders are connected with hinged bases on the bottom surface of the feeding plate in a rotating mode respectively, and a buffering mechanism is arranged on the inner side of the end, away from the cutting machine head, of the working table. The sliding grooves are formed in the working table, the hydraulic cylinders can drive the feeding plate to reciprocate during stretching and retracting, the rate of reciprocation movement is increased for the feeding plate, necessary time for cutting work is shortened, and the working efficiency in cutting is effectively improved.