Abstract: Miniature Joule-Thomson cryocoolers have been widely used for rapid cooling of infrared detectors，cryosurgery probes，thermal cameras，and missile guidance homing systems，due to their special features of simple configuration，compact structure and rapid cooldown characteristics.The thermodynamic performance of the J-T refrigerator depends upon the hydraulic and heat transfer characteristics of the recuperative heat exchanger.database is used to account for the real gas effects.The thermodynamic characteristics of the finned-tube Heat Exchanger are well revealed，based on this，the optimization analysis of miniature J-T cryocooler is carried out.The influences of mass flow rate and the length of heat exchanger on the effectiveness of heat exchanger and the ideal cooling capacity are discussed in details.