Abstract: To solve the problems of energy waste and hidden danger caused by ash in the convection section of chemical equipment, a washing machine was designed with walking, guiding and over obstacle functions on the furnace tube. The washing machine was also designed to carry a spray bar and to be able spray high-pressure water, cleaning the outer wall of the furnace tube. The spray bar was arranged to be freely adjusted to achieve full cleaning the outer wall of multi-furnace tubes in different layers. According to the structure of the washing machine and the work process, a control system was designed for the washing machine. The dynamics simulation of the washing machine was carried out, and the design parameters of the washing machine were optimized. A test platform and the prototype were built. Experiment results show that, the cleaning machine can run smoothly, and the furnace tube cleaning operation can be realized with the installed high-pressure water jet.