According to the process principle of VCF seawater desalination, the process design is made for the seawater desalination process unit using the Vapour Compression Flash method, and the theoretical calculation is performed for the process parameters. Based on the energy balance analysis of the seawater desalination process unit of Vapour Compression Flash, the heat flux distribution is calculated. The design and manufacture of the first VCF seawater desalination prototype has been completed, and the prototype successfully produced water with high purity. To perform an exergy analysis of the VCF seawater desalination system, a model has been set up. The system exergy efficiency and exergy loss of local sites are obtained via this calculation and provide the theoretical basis for system optimisation and equipment improvement. The most important factor can be determined from the exergy analysis. The rational selection and matching of the above factors is vital to increasing the water output and decreasing the electrical power using the VCF seawater desalination technology. This analysis provides a direction to improve the performance of the VCF seawater desalination device. (C) 2014 Elsevier B.V. All rights reserved.