Based on the historical data of Jiangsu Province, this paper predicts the elderly population of every city in Jiangsu, and the fiscal expenditure that cities incur in the field of public pension services according to the indicators of planning to achieve the improvement of pension services during the “13th Five Year”period. The paper also measures and predicts the efficiency of fiscal expenditure on public pension services in 2015 and 2025 respectively in Jiangsu province by using DEA model，in order to evaluate the influence that the improvement of pension service exerts on government fiscal sustainability with the index of public pension service expenditure efficiency. The research finds that: South cities of Jiangsu may cause negative impact on fiscal sustainability of the government during the process of improvement，due to too large scale of financial investment. The Central cities and North cities need to enlarge the scale of investment relatively. The government needs to optimize the expenditure structure in the overall financial investment process, improve management level, and raise the efficiency of capital use, in order to promote the sustainable development of finance.