Increasing seawater desalination concentration factor can improve the performance ratio and effectively reduce the post-treatment cost of the concentrated seawater that is reused，therefore，it is one of the keys to realizing low-cost zero discharge of seawater desalination.The experiment was carried out in a multi-phase circulating fluidization bed(CFB)evaporator.It aimed to study the effects of particle volume fraction on seawater desalination concentration factor and film heat transfer coefficient.The main components of the scaling were also analyzed.The operations of vapor-liquid two-phase boiling flow and vapor-liquid-solid three-phase boiling flow were investigated in the experiment.The results showed that calcium sulfate is the main component of the scaling，and it was firstly separated out in the seawater desalination experiment.In the vapor-liquid two-phase boiling flow，the film heat transfer coefficient was kept at 1.75 kW·m-2·K-1 and concentration factor reached 3.8.In the vapor-liquid-solid three-phase boiling flow，the result revealed that solid particles remarkably enhanced heat transfer and improved the prevention and removal of fouling.When particle volume fraction was 4% and film heat transfer coefficient was kept at 2.3 kW·m-2·K-1，seawater desalination concentration factor reached more than 5.8.