In order to improve the heat transfer performance of the evaporator in the cold storage refrigeration system，a new type of plate evaporator was designed.The influence of refrigerant mass flow rate and air side velocity on the heat transfer characteristics of the plate evaporator was discussed by using the method of simulation combined with experiments，and an optimized structure with an intermediate channel was proposed.The heat transfer characteristics of the plate evaporator were studied when the inlet dryness of refrigerant R22 was 0.27，the temperature was -5 ℃，the saturation pressure at this temperature was 0.421 8 MPa，the mass flow rate was 0.017 kg/s，the air inlet temperature was 6 ℃，the relative humidity was 80%，and the flow rate was 3 m/s.The results show that in the design conditions，the cooling capacity in this design condition is 2.86 kW，the refrigerant side pressure drop is 1 150 Pa，and the air side pressure drop is 412 Pa.As the mass flow rate of refrigerant increases，the cooling capacity increases，but the growth rate slows down significantly after reaching 0.017 kg/s.The pressure drop on the refrigerant side also increases，and the growth rate gradually increases.As the inlet flow rate on the air side increases，the cooling capacity increases，but the growth rate slows down significantly after reaching 3 m/s.The pressure drop on the air side also increases，and the growth rate gradually increases.The refrigerant mass flow rate should match the air inlet conditions.Compared with the original structure，the plate evaporator with a middle connected structure has increased cooling capacity by more than 9.4%，increased refrigerant side pressure drop by 18.3%，and increased air side pressure drop by 20.2%.The intermediate connected structure can improve the heat transfer performance of the evaporator.The research results can provide reference for the study and design of evaporators in cold storage refrigeration systems.