The utility model provides a binary channels raise dust monitor, including particulate matter sample separating module, binary channels particulate matter detection module and double - circuit constant current control module, there are two tunnel conveying line that are used for supplying the outside air to get into among the particulate matter sample separating module, conveying line for being used for monitoring PM2.5 concentration of the same kind, the conveying line of another way for being used for monitoring PM10 concentration, PM2.5 concentration conveying line and PM10 concentration conveying line respectively with binary channels particulate matter detection module in two monitoring channel be connected and communicate with each other, two monitoring channel are connected with double - circuit constant current control module communicate with each other simultaneously. The utility model discloses can carry out two parameter detections of PM2.5 and PM10 to the air that comes by the transport of particulate matter sample separating module simultaneously, in other words, the utility model discloses an original two work that the instrument could be accomplished can be accomplished simultaneously to the platform instrument, and consequently, area is less relatively, and whole cost is also cheap relatively, and it is all very convenient that maintenance and use are got up.