In consideration of high temperature and high salinity of the thin oil reservoirs in Jianghan Oilfield and poor performance of common surfactants under such conditions, a series of SH anionic-nonionic surfactants，C12H25O(CH2CH2O)nCH2CH(OH)CH2SO3Na (the SH01~SH05 was corresponding to n value of 5~9），were synthesized. Their properties such as surface activity, temperature resistance, and salt tolerance were measured in laboratory, and oil displacement efficiencies were evaluated with physical models. The experimental results showed that the synthesized surfactants have fine temperature resistance and salt tolerance, and the oil-water interfacial tension became even lower as temperature and salinity increased. The interfacial tension between the oil from Zhongshi Oilfield and the aqueous solution having high salinity of 300g/L and surfactants of 0.3% could descend to an ultra-low order of 10-3 mN/m. The physical simulation experiments showed that when injecting 0.3 PV the 0.3% SH-3 solution alone, oil displacement efficiency could be enhanced by 6%; while the combination flooding system(0.3% SH03+0.3% SMG) could enhance the oil displacement efficiency by 12.1%. The Zhong10-5 Wellblock in Zhongshi Oilfield was chosen to carry out the pilot test and yielded a good result of increasing oil.