PM2.5 monitor suitable for high-humidity environment

The utility model discloses a PM2.5 monitor suitable for a high-humidity environment. A dehumidifier is arranged on the outer side of a first separation device of the PM2.5 monitor, and moisture of particles which enter the first separation device is rapidly removed through the dehumidifier, so that the influence of a humid environment on monitored data is eliminated. In addition, a filter membrane is driven by rollers on two sides of a beta radioactive source, filter paper is not required to be moved in a measurement process, and the measurement precision and stability are improved. Compared with the prior art, the PM2.5 monitor can operate in the high-humidity environment and has the advantage of accurate and reliable testing data.