Abstract: PLC control system of uniform velocity temperature rise based on idea of devide and conquer was designed based on considerations of practicability, low-cost and high-precision control. The system devided the heating process into multi sub-units, and calculated heating time and set temperature for each sub-unit, and finally execute heating sub-unit successively. Least squares method was used to fit temperature curve, and the error of temperature rise rate between fitting temperature curve and theoretical temperature curve was 3.62%, it indicated that the system has high precision control and small error of temperature rise rate.