In order to effectively deal with the oil water separation problem of surfactant/polymer（SP）binary flooding emulsion containing solid particles，the effects of diatomite，demulsifiers，partially hydrolyzed polyacrylamide（HPAM）and petroleum sulfonate surfactant on the stability of produced fluid and interfacial property of Shengli offshore crude oil SP flooding were investigated using interface tension tester and turbiscan LAB analyzer. The results showed that a compound demulsifier FP had good demulsification effect，which composed of nonionic demulsifier ECY-05 and organic silicon demulsifier 589 with mass ratio of 4∶1. The stability of the emulsion and the interfacial tension decreased and the dehydration rate increased with increasing dosage of FP. When the mass concentration of FP was 200 mg/L，the dehydration rate of crude oil emulsion with diatomite reached 88% in 60 minutes. With the increase of HPAM，surfactant and diatomite content，the stability of emulsion increased and the dehydration rate decreased. The interfacial tension between oil and water increased with the increase of diatomite，while that decreased with the increase of surfactant. HPAM had little effect on the interfacial tension. The synergistic effect of the three made the dehydration rate lower.