The invention provides a measuring device and a measuring method for powder matters. The measuring device comprises a measuring box, a vibration mechanism, a laser generation device, a material feeding device and a light collection device, wherein the laser generation device, the material feeding device and the light collection device are arranged in the measuring box; the vibration mechanism is used for driving the measuring box to vibrate; the powder in the material feeding mechanism flows downwards into a measuring chamber formed in a box body through a feeding port; the laser generation device and the light collection device are arranged in the measuring chamber; the laser produced by the laser generation device is transmitted to a powder curtain column formed by the powder in the falling process; the light collection device is used for collecting a light signal after radiating, and converting into an electric signal to be transmitted out. The measuring device has the advantages that the structure is simple, the measuring steps are rapid and convenient, and the accuracy is high.