The double-layer stainless steel reaction kettle is a commonly used biochemical instrument, widely used in modern fine chemical, biopharmaceutical, scientific research and experimental industries. It can perform concentration, distillation, reflux, separation, and purification reactions under constant speed, constant force, and constant temperature conditions. It is an ideal instrument and equipment for teaching, experimentation, pilot testing, and production. By injecting a constant temperature (high or low temperature) hot solution or coolant through the double-layer reactor interlayer, the materials inside the reactor can be heated or cooled at a constant temperature, and stirring can be provided. The material undergoes a reaction in the reactor and the evaporation and reflux of the reaction solution can be controlled. After the reaction is complete, the material can be released from the discharge port at the bottom of the reactor, making it easy to operate. It is an ideal equipment for modern chemical sampling, petrochemicals, medium scale experiments, biopharmaceuticals, and new material synthesis.