The invention provides a fastening and connecting device. The fastening and connecting device is used for fastening a first fastened part and a second fastened part together in a threaded connection mode, and comprises a first fastening part and a second fastening part. Before screwing is performed, the first fastening part can be preassembled with the first fastened part, and the second fastening part can be preassembled with the second fastened part. The second fastened part can be preassembled with the second fastening part in a clamping fit mode so that the second fastening part and the second fastened part cannot relatively rotate under the preassembly state in the thread screwing process.