A continuous screen changer, including: an external shell having an internal cavity, and an internal drum. The external shell is provided with a feed port, a screen changing port, and a discharge port. The internal drum is provided with at least four filter screen mounting grooves and material flow passages correspondingly communicating with the filter screen mounting grooves. A sealing wall hermetically connected with the internal cavity is formed between each two adjacent filter screen mounting grooves. Whichever of the filter screen mounting grooves is opposite to the feed port rotates to be opposite to the screen changing port in a rotation process, and whichever of the filter screens is on said filter screen mounting groove opposite to the screen changing port is changed at the screen changing port