PM2.5 (particulate matter 2.5) detection warning device and method

The invention discloses a PM2.5 (particulate matter 2.5) detection warning device and method. The device comprises a PM2.5 cutter, a drier, an optical measuring cavity, a central processing unit, a storage module and a warning module, wherein the optical measuring cavity comprises a filtering membrane, a laser detector, a gathering lens and a photoelectric detector which are arranged in the cavity; the output end of the PM2.5 cutter is connected with the filtering membrane arranged in the optical measuring cavity through the drier; laser given out by the laser detector passes through the filtering membrane and is then gathered to the photoelectric detector through the gathering lens; the photoelectric detector is connected with the central processing unit. The device and the method adopt a laser scattering method for measuring the PM2.5 concentration, so that the cost is greatly reduced, the manual operation is not needed, the efficiency is high, the influence by temperature and humidity is small, and the detection precision is high; in addition, a PM2.5 detection technology is combined with a warning technology; a wireless transmission module and the warning module are adopted; relevant units and individuals can be timely notified when the PM2.5 concentration exceeds the standard; the body health of users can be favorably protected.