China's box change was originally developed from the European-style box change, and its volume is often relatively large. With the opening of China's foreign economy and the vigorous development of the market economy, in the 1990s, American box change entered the Chinese market and achieved rapid development in the Chinese market with its unique characteristics. From south to north, from east to west, you can see this kind of American box change almost everywhere in China, and most of them are counterfeit products from domestic manufacturers, and the quality can be said to be uneven. Through the application and practice of these years, it is necessary to carefully analyze the combination of American box transformers and China's national conditions and give the correct positioning, so as to promote the technology and market development of China's box transformers.