Through design of balancing movement controller of large size workpiece for applying to LDMC-100 type ion nitriding furnace, the structure and principle of mechanism were introduced, the balance of mechanical transmission and influencing to nitriding layer of workpiece surface were analysed. In this mechanism, the planetary gear system was adopted, the single axis was adopted in this supporting mechanism, and the electric and insulating on workpieces were used. The balancing influencing of movement and techniques parameters for nitriding layer were discussed. The results indicate, the nitriding period is related with input speed and number of driven gear teeth. The re-nitriding rate and blank nitriding rate are related with gear modulus, workpiece outside diameter, number of drive and driven gear teeth. When the mechanism structure parameter is fixed, the effect of nitriding was completed by changing speed of input axis.