To solve the compaction mechanism problems such as insufficient steering shaft strength stiffness caused by partial load， the force method and the displacement method in structural mechanics are used in compaction mechanismguide shaft structure size design， and the design parameters and the formula of the statically indeterminate structure under symmetrical loading arededuced.The designed compaction mechanism oriented axis is analyzed in three-dimensional contact finite element analysis by using finite element analysis software Abaqus. Stress and deformation under full load conditions are studied. Results show that the guide shaft deformation is smallwhen the compaction mechanism in full load conditionand the stress on the guide shaft in all directions are less than the allowable stress.Research methods and results will provide guidance for designing the compaction mechanism guide shaft.