Abstract: The shield planetary reducer is an essential component in the drive system of the shield machine, and is the main transmission device in the excavation system of the shield machine, used to connect the cutterhead and hydraulic motor. This article conducts strength and shape modification calculations and analysis on the structure of the designed shield planetary reducer scheme. Based on the MASTA transmission analysis software, fatigue and static strength checks are carried out on the gear and bearing parameters. At the same time, micro shape modification optimization schemes for gears are obtained for different working conditions. Strength analysis of each main structural component is carried out using Abqus finite element analysis software. After analysis, the relevant parameters and structures designed can meet the requirements for use.