The novel lithium sulfur (Li-S) battery is widely concerned owing to its ultrahigh theoretical energy density of 2600 Wh/kg. However, its commercial application has been obstructed by the rapid decline of capacity and short cycle life, which is mainly because of the dissolution behavior of polysulfides into electrolyte solution and subsequently continual shuttling effect. Some strategies including carbon carriers for loading sulfur, modification of electrolyte and overall structure design of cell are brought forward to overcome the inherent defects of Li-S battery. Modified separators with multifunctional layer are also investigated extensively and benefit from their simple preparation method and enhanced electrochemical properties. Herein, nanosized Ti4O7 supported on mildly oxidized carbon nanotubes (oCNTs-Ti4O7) composite was synthetized and coated on the surface of separator to form modified layer, which is combined with the electrically conductive network structure of CNTs and effective adsorption of Ti4O7 nanoparticles. Compared with common separator, the modified separator with oCNTs-Ti4O7 layer can significantly improve the utilization of active substances as an additional current collector and restrain the shuttling effect of polysulfides by combination of physical obstruction and chemical adsorption. The Li-S battery has made great enhancements in electrochemical properties including cycle and rate performance. In particular, the cell using oCNTs-Ti4O7 separator has released specific discharge capacities of 888 and 658 mAh/g at a current density of 0.5C for the 1st and 250th cycle with a capacity retention of 74.1%. In the rate performance test, a discharge capacity of 586 mAh/g is still remained even at a high current density of 2C. Meanwhile, the test results of diffusion behavior indicate that the modified layer would not affect the normal transmission of lithium ions.