It is found that under the pay-as-you-go system, from the perspective of different pension insurance system design, increasing the number of children will reduce the level of pensions.According to the prospect of different pension system design, under the salary system, increasing the number of children will reduce the pension level.It is found that in the context of the pay-as-you-go system, the number of children is reduced by increasing the number of children by increasing the number of children.