PM2.5 refers to the particulate matter in a diameter smaller than or equal to 2.5 micron, also known as “fine particulate matter”. It has a lot of effects on human health and environmental quality due to its small volume, rich contents of toxic and harmful substances, long stay in air and long distance of transport. This design uses microcontroller as the controller, combined with the dust sensor GP2Y1010AU0F, A/D converter, wireless transceiver module, clock module and LCD, enables the host to collect and transport the outdoor PM2.5 in realtime, and enables the slave to display the dust concentrations, air quality standard, time, temperature using scale transformation and prompt the outdoor travel on LCD in realtime. Date comparison in the system debugging process shows that the design features simple structure, low cost, visual display and other, which can be somewhat referential for the realtime monitoring of PM2.5.