In order to reduce the temperature in the furnace, the physical and mathematical model of the cooling horizontal coiled tube was established. Flow Simulation software was used to simulate the cooling copper tube in the heating process. The results show that different fluid flow types in horizontal coiled tube have different cooling effects on copper plate. As the coiled tube is placed horizontally, the temperature around the cooled copper plate is lower, and the temperature closer to the center is higher. For singlephase working medium water, the wall temperature of the horizontal serpentine tube is increasing along the length of the tube, but it decreases slightly at the elbow, and shows an overall trend of rising. The wall temperature increases with the decrease of mass velocity, and the wall temperature increases more obviously at lower mass velocity. The research results provide reference for practical application