The main driving force of this development comes from international investment. This can be considered from three aspects: first, at the level of industrial structure, international investment has promoted the development of related service industries in various countries, thus expanding the scope and content of international service trade. If the traditional direct investment develops into various forms of international indirect investment, it will inevitably require the rapid and perfect development of financial services in various countries. The development of international investment also requires the effective development of information, consulting, leasing, labor export and import and other related services. Second, transnational investment has strengthened the dependence of national economies, and the demand for each other's service industries has also increased. Third, the net income of international investment (direct investment and indirect investment) itself constitutes a content of generalized service (capital factor service). According to the statistics of the International Monetary Fund (IMF) in 1986 when countries decided to promote multilateral negotiations on service trade, the international service trade of IMF member countries reached 404.9 billion special drawing rights that year, equivalent to 25% of the total world trade in that year, and the return on capital (net income from various investments) accounted for about 1 1.7%.