A temperature accurate control device used for an integrated cavity spectrum technology isotope analysis comprises a one-time sealing shell of an optical path system and a second-time sealing system of temperature stable and accurate control. The optical path system is installed inside the one-time sealing shell and the temperature accurate control device is characterized in that an optical laser, a distributed feed back (DFB) optical laser light source, a light beam converging collimating lens assembly, a laser path, an optical cavity, a laser beam converging lens and an InGaAs detector are integrated inside the optical path system. The optical laser, the DFB optical laser light source, the light beam converging collimating lens assembly, the laser path, the optical cavity, the laser beam converging lens and the InGaAs detector are all in the nitrogen condition to be prevented from being interfered by outside gas. The second-time sealing system of the temperature stable and accurate control comprises a second-time sealing shell, platinum resistor temperature sensors, rigid supports, semiconductor refrigeration piles, net-shaped heat exchangers, fans and shock absorption foams and further comprises a temperature controller, a driving circuit module, wherein the temperature controller and the driving module are arranged outside the second-time sealing shell and various control commands and electrical signals are all connected in a sealed mode through cables. The temperature accurate control device used for the integrated cavity spectrum technology isotope analysis has the advantages of being simple in structure, convenient to operate, quick in response, good in resistance to shock, high in temperature control precision and good in stability.