Hydrothermal synthesis reaction kettle, also known as polymerization reaction kettle, includes high-pressure digestion tank, high-pressure tank, reaction kettle, pressure dissolution bomb, digestion tank, hydrothermal synthesis kettle, and experimental reaction kettle. A hydrothermal synthesis reactor is a closed container capable of decomposing insoluble substances. Can be used for sample pretreatment in atomic absorption spectroscopy and plasma emission analysis; It can also be used for low-dose synthetic reactions; The purpose of rapidly dissolving insoluble substances can also be achieved by using a sealed environment with strong acid or alkali inside the tank and high temperature and high pressure. Sample pretreatment is performed in chemical analysis methods such as gas phase, liquid phase, plasma chromatography-mass spectrometry, atomic absorption, and atomic fluorescence. It is a powerful assistant for the determination of trace elements and the digestion of samples during trace element analysis. It can be applied in the determination of heavy metals such as lead, copper, cadmium, zinc, calcium, manganese, iron, mercury, etc. It can also be used as a high-temperature, high-pressure, corrosion-resistant, high-purity reaction vessel, as well as in organic synthesis, hydrothermal synthesis, crystal growth, or sample digestion and extraction. Dissolve heavy metals, pesticide residues, food, sludge, rare earths, aquatic products, organic matter, etc. before sample preparation. Therefore, it is widely used in research and production in departments such as petrochemicals, biomedicine, materials science, geochemistry, environmental science, food science, and commodity inspection.