Disclosed is a folding and expanding portable pet crate. The pet crate comprises a crate top plate, a crate bottom plate and quadrilateral front, left, right and rear side walls respectively connected to the four sides of the bottom plate. The crate top plate is connected to the front side wall, edges of the left side wall and the right side wall are respectively equipped with quadrilateral support frames. The front side wall, the crate top plate and the rear side wall are all connected to the left side wall and the right side wall via a first zip fastener to form a closed pet crate. The first zip fastener comprises a cloth tape A and a cloth tape B meshing with each other, the cloth tape B being sewn to a side edge of the front side wall, the crate top plate and the rear side wall and after turning 180 degrees from the front side wall, the cloth tape B fits with the bottom part of the crate top plate. The left and right sides of the pet crate respectively connect the crate plates on the various sides by means of two sections of zip fastener to form a pet crate. Assembly and folding of the pet crate are very convenient, also facilitating folding and unfolding. The pet crate takes up a small amount of space, facilitating carriage and storage； and can replace pet cages for daily use, is more portable than a pet cage and is convenient to move.
