The utility model provides a fine coal pipeline prevent stifled device. Include: the coal -grinding trunk line, pipe chute and detection device, the coal -grinding trunk line sets up perpendicularly, sets up the opening on its lateral wall, it is continuous with detection device's interface that the opening passes through the pipe chute. Adopt oblique inserting type buggy pipeline temperature measurement mouth to connect to locate the setting at the connector and sweep nitrogen gas, guaranteed the accuracy of instrument measurement station and used the permanence. Buggy pipeline measurement station not happening leads to inaccurately because of blockking up the reason. Easily clear up the buggy that stores up in taking over during the parking. This device easy operation, it is with low costs, be convenient for maintain.