Polymerizing kettle bottom valve replacement method and replacement improvement system

The invention discloses a replacement method and a replacement improvement system for a bottom valve of a polymerization kettle. The replacement method comprises the following operation steps: S1, reducing the pressure of the polymerization kettle of which the bottom valve is to be replaced; s2, determining whether the polymerizer has a condition of replacing a bottom valve or not; s3, before the bottom valve is detached, a heat preservation part is detached, and a body is completely exposed; s4, placing the polymerization kettle on a hydraulic lift truck support arm, moving and lifting the hydraulic lift truck support arm until the hydraulic lift truck support arm completely supports the hydraulic bottom valve; s5, connecting flanges of all parts of the auxiliary pipeline are disassembled, the hydraulic arm is descended, the bracket and the bottom valve are descended to the lowest position at the same time, and the disassembling process is finished; s6, moving the hydraulic lift truck to a designated positio