A threshing device (3), comprising a threshing chamber, a threshing cylinder (304), and a threshing cylinder shaft (316). A first processing space (312) is formed between the inner wall surface of the threshing chamber and the threshing cylinder (304). The interior of the threshing cylinder (304) is provided with a second processing space (313) and a closed assembly, the second processing space (313) communicating with the first processing space (312) and used for entrance of an object to be threshed, and the closed assembly enclosing the threshing cylinder shaft (316) and separating the threshing cylinder shaft (316) from the second processing space (313). According to the threshing device (3), by means of the communication between the second processing space (313) and the first processing space (312), the object to be threshed can enter the first processing space (312) and the second processing space (313), so that the space of the threshing chamber that can contain the object to be threshed is enlarged, and the processing space is not easy to be filled completely, thus the threshing load can be reduced, the processing capacity of the threshing device (3) is greatly improved, and the object that is not threshed is prevented from being discharged out of the device caused by the object to be threshed being pressed to a non-processing space.