The application provides a content addressable memory (CAM) cell, a CAM memory device and an operation method thereof, and a method for searching and comparing data. The CAM cell includes a first flash memory cell having a first terminal for receiving a first search voltage; and a second flash memory cell having a first terminal for receiving a second search voltage, a second terminal of the first flash memory cell electrically connected to a second terminal of the second flash memory cell, wherein the first flash memory cell and the second flash memory cell are serially connected; and a storage data of the CAM cell is based on a combination of a plurality of threshold voltages of the first flash memory cell and the second flash memory cell.