Abstract: The rules of digital trade are not only the core issue of regional trade agreements, but also important driving force promoting the high-level opening-up of countries around the world. By measuring the overall structure and centrality indicators of the digital trade rule network of regional trade agreements (RTAs) signed by“the Belt and Road”countries, this paper systematically analyzes the evolution of the network and the status and influence of each node country in the network. Based on the regional trade agreements that came into effect from 2010 to 2021, this paper constructs a multi period double difference model to empirically analyze the impact of digital trade rules on the scale of digital trade, then further explores their mechanisms and regulatory effects. The findings show that compared to 2010, the network size of digital trade rules has significantly expanded in 2021, with an increasing number of countries participating in rule making. The EU member states among “the Belt and Road”building countries have the highest central position and strongest influence in the network. The digital trade rules significantly promote the expansion of digital trade scale, and the promotion effect is more significant when both sides are“the Belt and Road”building countries or they agreements include digital trade privacy protection clauses. The rules of digital trade are playing their roles mainly through two channels: shortening the institutional distance and improving the level of information and communication technology development. The countries with smaller gap in digital infrastructure, research and development level, and economic development level have stronger promotion effect on the scale of digital trade after signing digital trade rules. Based on this, the countries jointly building“the Belt and Road”should strengthen the construction of digital infrastructure, actively participate in the formulation of international digital trade rules, and deepen“the Belt and Road”digital trade cooperation.

Key words: “The Belt and Road”, digital trade rules, scale of digital trade, multi-period DID