Abstract: In order to achieve boiling distillation and to reduce the internal fouling,this paper design a direct heating desalination system with compound Parabolic concentrator（CPC）. CPC is employed to heat conduction oil in the system. The salt water is effectively heated and rapidly vaporized by working fluid in the heat exchanger,after that,steam condenses into fresh water in the condenser. The maximum oil temperature at the inlet of the distiller reaches 118.1 ℃ in sunny summer weather. The internal temperature of the distiller reaches 94.8 ℃ at 11:00 am,which is higher than the local boiling point and can last until 16:30. The instantaneous heat collection efficiency of the desalination system is 51%,the water yield under the total effective solar collection area is 7.23 kg/d,the TDS of the produced water undulates but always keeps blow drinking water standards. The effective energy utilization of the desalination system is beyond 0.5 from 12:00 am to 16:30 pm,with a maximum of 0.63 at 16:40 pm.