The application relates to an air conditioner/heat pump expansion function box and an air conditioner/heat pump heat storage refrigeration system, and belongs to the technical field of air conditioner/heat pump systems. Two distribution pipelines are arranged in the air conditioner/heat pump expansion function box body; each distribution pipeline comprises a main pipeline and at least one branch pipeline; the two ends of each main path are provided with an outdoor unit nut head and an indoor unit nut head respectively. The end portion, far away from the main path, of each branch path is provided with a radiation assembly nut head; an outdoor unit nut head is connected with an outdoor unit, an indoor unit nut head is connected with an indoor unit, and a radiation assembly nut head is connected with a radiation assembly. Therefore, an air conditioner/heat pump heat storage refrigeration system is formed, reasonable distribution of water-free floor heating pipelines is achieved, the energy efficiency ratio of the air conditioner/heat pump system is increased, pipeline connection of a unit is achieved under the non-oxidation condition, it is guaranteed that no impurities exist in the system pipelines, the service life of the unit is long, the assembling efficiency is improved, no welding process exists on site, operation is easy, and the appearance is attractive.