The invention discloses a medical instrument and particularly relates to a spine internal fixation non-fused dynamic connection rod. The spine internal fixation non-fused dynamic connection rod comprises an elastic rod and is structurally characterized in that the two ends of the elastic rod are of hollow structures, the middle and the two ends of the outer wall of the elastic rod are provided with first hollow threads, second hollow threads and third hollow threads respectively. A first shell, a second shell and a third shell are in threaded connection at the three hollow threads respectively. A second connection mandrel, a second upper spring, a second sealing cap, a first connection mandrel, a first upper spring and a first sealing cap are sequentially and tightly installed in one end of the elastic rod in a matched mode. A third connection mandrel, a third upper spring and a third sealing cap are sequentially and tightly installed in the other end of the elastic rod in a matched mode. The spine internal fixation non-fused dynamic connection rod has the advantages of being convenient to operate, simple in adjustment, safe and reliable in use and capable of providing stability of the spine and keeping the mobility of the spine.