The fresh-keeping transportation container with controlled atmosphere by liquid nitrogen injection is an advanced and efficient equipment for transporting fruits and vegetables. The temperature of liquid nitrogen is -196℃. When liquid nitrogen was injected directly into the container, fruits and vegetables would be damaged. A heat exchanger with low control precision of the outlet temperature was used in the container. In order to improve the control precision of the outlet temperature of heat exchanger and utilization rate of cold quantity, a liquid nitrogen injection heat exchanger capable of storing energy was designed. A test platform was set up to study the effects of copper tube length, the type of phase change materials and liquid nitrogen flow rate on the operation characteristics of the heat exchanger. Based on heat transfer theory, a calculation model for heat exchanger outlet temperature was established. Calculated value was basically consistent with the experimental value, and the relative error values were 2.01% and 8.06%. The test results showed that the copper tube length, the type of phase change materials and liquid nitrogen flow rate had a significant effect on the operation characteristics of the heat exchanger, the copper tube length and liquid nitrogen flow rate had linear relationship with the injection time. When the copper tube length increased or the liquid nitrogen flow rate decreased, the linear relationship correlation coefficient was higher. When the coil length was 3m, the liquid nitrogen flow rate was 0.0075kg/s and the phase change materials was water, the heat exchange efficiency of heat exchanger was better. When the coil length was 3m, the liquid nitrogen flow rate was 0.01kg/s and phase change materials was water, the thermal storage efficiency of heat exchanger was better. The results provided references for control outlet temperature of heat exchanger accurately and recycle of cooling capacity.