The present invention discloses a novel hydrophilic and compressible aerogel as draw agent for purification water in forward osmosis (FO), which belongs to environmental pollution control engineering technical field. The improved performances are obtained by optimizing regeneration process of drawing and producing water by using this aerogel as a draw agent in FO technology. Herein, the aerogel complete avoid the draw solution's reverse diffusion and maintain a higher water flux that compensates for its structure characteristics. Moreover, the regeneration of the draw agent and production water should be accomplished through human compression without a complicated physical and chemical method. Simultaneously, this draw agent presents other advantages of wide raw material sources, low cost, wild preparation process, low poison and good film compatibility. It is an innovation as FO technology in portable water purifying device, especially in areas of military and emergency.