This paper uses counter-factual analysis to study the impact of national pooling basic pension on the redistribution of pension funds and the financial burden. The study found that no matter what kind of payment plan, the national pooling through the cross-provincial adjustment of basic pensions, not only reduces the pension benefits of high-income provinces but also increases the pension benefits of low-income provinces. If national pooling eliminates inter-provincial differences and uses the national average wage as the basis for calculating pension benefit. Then the amount of basic pensions transferred across provinces will be the largest. However the resistance of national pooling policy and the financial burden are also the heaviest. Therefore, the selection of the optimal payment plan must not only allow the insured to share the benefit of national economic development, but also consider the provincial differences in pension benefits. By weighing the amount of funds transferred across provinces, policy implementation resistance, and financial burdens, three factors are used to determine the optimal benefit plan.