Taking starch, acrylic acid and acrylamide as raw material, ammonium persulfate and sodium bisulfite as initiator, DJ-1 with unsaturated double bond organic compound as crosslinking agent, a water-soluble fracturing temporary blocking agent was synthesized and its properties were characterized. The results showed that with increasing temperature and prolonging dissolved time, the solubility of temporary blocking agent in formation water increased. When the solid-liquid (formation water) ratio was 1:300, the water soluble rate of temporary blocking agent in 16 hrs was 96%—98% at 20—80℃, which indicated good water solubility. After complete dissolution, the viscosity of 5—20 g/L solution was 12.6—53.7 mPa·s, which had good flow back. The tensile strength of 20 g/L solution of temporary blocking agent was 9.1 N, which had good adhesion ability. The results of core experiment showed that the blocking strength of temporary blocking agent decreased with increasing core permeability. The maximum pressure gradient of temporary blocking agent was 47.1 MPa/m, which had the ability of sealing original cracks, making the maximum principal stress deviating, and then generating new cracks. The plugging rate of temporary blocking agent on the core was greater than 90%, and the recovery rate of core permeability after formation water flushing was up to 97.6%. The selectively plugging rate of temporary blocking agent on high permeability layers was greater than 83.2% and that increased with increasing core permeability contrast.