The China International Import Expo is an important platform for international procurement，investment promotion，cultural exchanges，and open cooperation. It is also a window for China to build a new development pattern，promote high-level opening up to the outside world，and provide globally shared international public goods. In order to fully utilize the four functions of the CIIE and strengthen its three major positioning，China continuously optimizes its fiscal and tax system to support the CIIE and promote high-standard opening up to the outside world：fiscal and tax policies work together to build a new development pattern “window”；Optimize the tax service system and promote the construction of high-level platforms for opening up to the outside world；Deepen international tax cooperation and provide high-quality international public goods. In this process，due to the complexity of transactions on the CIIE platform，the uncertainty of the foreign economic and trade cooperation environment，and the variability of transaction modes，the design and operation of relevant fiscal and tax system have also encountered some difficulties and exposed some problems，including the challenge of further improving the accuracy and timeliness of fiscal and tax policy formulation；Tax services and tax administration face the challenge of balancing efficiency and security；In the context of globalization，international tax cooperation faces challenges of continuous deepening and expansion. In this regard，in the future，the focus of promoting the opening up of the CIIE and steadily advancing the fiscal and tax system should be on：improving relevant fiscal and tax policies and supporting measures，enhancing policy accuracy and timeliness；Further optimize tax services and tax administration，improve administration efficiency and security；Deepen international tax cooperation，strengthen and expand the connectivity and spillover of cooperation networks.