In this paper, we derive the optimal cyclical design of a target benefit (TB) pension plan that balances the sustainability and the benefit stability using the optimal control approach. The optimal design possesses a linear risk sharing structure with cyclical parameters. We observe that the optimal design should be pro-cyclical in the usual circumstances, but counter-cyclical when the pension plan is severely in deficit. We compare the TB plans with the defined benefit plans and conclude that a more aggressive investment strategy should be adopted for the TB plans. In the end, we provide a cautionary note on the optimal control approach in the study of the TB plans.