To reduce the excessive consumption of metal minerals and boost the development of the circular economy, scrap metals are increasingly recycled across the world. Due to the geographically uneven distribution of scrap metals, most countries are actively participating in the international scrap metal trade. This study collects international trade records on scrap metals from 1988 to 2017 and constructs the annual global scrap metals trade network (GSMTN) to analyze the characteristics and dynamic evolution of the scrap metal trade. The results reveal a globalization trend of the scrap metal trade, the scale-free characteristics of the trade network, and the increasing monopolization of the export market. The international scrap metal trade has experienced a dynamic evolution in the past 30 years and has developed into a complex system with a hierarchical structure that is led by a few core countries. Three relatively stable groups are the main players in the international scrap metal trade: East Asia-America-Oceania, Europe, and South Asia-Middle East. A review of the split and merger process of these communities clearly shows that geopolitics and economic turbulence are important elements in the fragmentation and integration of trade communities. The findings will enable governments to understand the complex trade relationships involved in scrap metals, which can help policy-makers propose effective import-export policies and ensure national resource security.