Introduction: I do n’t know when and when the haze in the sky has spread the word PM2.5 to everyone. Facing the "open door ash" encountered in the beginning of 2013, PM2.5 is deeply in people's minds. With similar reports such as "The national haze area has expanded to 1.43 million square kilometers", "PM2.5 bursting in various places" and other similar reports continue to impact people's patience bottom line, how to deal with it? How to monitor? That is our next important task. Faced with increasingly serious environmental pollution, industry insiders predict that the Chinese government will soon launch a 100 billion yuan investment in air pollution control activities. In this issue, let's take stock of the PM2.5 governance detection technology and related environmental protection companies that have been the focus of the market.