In the last two years, environmental protection requirements for enterprises have become increasingly high in China. The restrictions have been implemented everywhere. On the one hand, the company's environmental tax increases the production cost, which leads to the rise of PCB price. On the other hand, the development of smart technology promotes the demand growth of PCB. Many small and medium-sized enterprises have been eliminated or acquired due to tight supply. This paper discusses the deep reasons for the promotion of PCB industry from the aspects of restriction, price increase, elimination or merger.