The negative pressure precision welding research and development platform utilizes the negative pressure environment to improve the utilization of laser energy. Simultaneously, the changes in the molten pool flow mechanism and pore behavior during negative pressure welding make the keyhole more stable, reduce the presence of gas pore defects in the weld seam, and improve the quality of the weld seam. It enables the welding or shaping and repair of large and complex structural components made of materials such as titanium alloy, aluminum alloy, high-temperature alloy, stainless steel, and carbon steel. There is a wide application demand for this technology in high-tech manufacturing fields such as aerospace, transportation, new energy, and nuclear power.