Powder material online automatic sampling device and automatic sampling method

The invention provides a powder material online automatic sampling device and an automatic sampling method. The powder material online automatic sampling device comprises a speed adjusting direct current motor 1, a transmission mechanism, a main bearing seat 2, a screw propeller 3, a screw outer shell 4, a sample storage barrel 8, an electronic weigher 9, a PLC controller 10 and an input and displaying unit 11. The PLC controller is used for adjusting the rotation speed, the working time, the stop time and the rotation frequency of screwing of the sampling device, sampling can be performed by changing time, quantity and periods, and also, the sampling can be performed with fixed time, fixed quality and fixed periods. Thus, the sampling can be performed continuously, stably, efficiently, safely, scientifically and accurately.