Calcium chloride hexahydrate (CaCl2•6H2O) is an important inorganic phase change material used for thermal energy storage or discharge at lower storage temperature. Thermal energy discharge characteristics of a new type of PCM heat exchanger were investigated after thermal energy storage, in which its main body is based on the traditional structure of a shell-and-tube heat exchanger, and is full of PCMs (CaCl2•6H2O) in the tubes. The cold air of 16-17°C with different velocities flowed through the PCM heat exchanger, the temperature distributions of all the test points were measured by means of the experimetal system. The experimental results showed that, since the latent heat of phase transition in the tubes was so large during the process of thermal energy discharge, the time intervals of air temperature that maintained beyond 20°C at the outlet of the PCM heat exchanger were respectively 594min and 717min when the mass velocities of the cold air were 0.132 kg/s and 0.096kg/s, which is one of the important characteristics in the structure of this type of PCM heat exchanger. It can be used in the situations of temperature control or maintenance at the certain temperature, such as greenhouses, air conditioning etc.