Abstract: The present invention discloses a flooded type evaporating heat-exchange copper tube for an electrical refrigeration unit. The evaporating heat-exchange tube comprises a smooth surface portion, a finned portion provided with plurality of fins and a transitional portion connecting the smooth surface portion to the finned portion, with primary evaporating chambers defined between the fins. Fifth fins extending upwardly are provided on a bottom wall of the primary evaporating chamber, which divide the primary evaporating chamber into at least two minor cavities, and an evaporating opening is defined between adjacent fins of the primary evaporating chamber. Due to plurality of minor cavities arranged in the evaporating heat-exchange tube, refrigerant film is easy to form on bottom walls of the minor cavities, and nucleus boiling is easily to be developed. Thereafter, the refrigerant gets boiled and evaporated to form bubbles to escape via evaporating openings.