Helium(He) is a scarce and strategic resource, and its source is mainly dependent on heliumcontaining natural gas. The helium content of natural gas in China is extremely low, making it challenging and costly to extract. Membrane gas separation is an efficient extraction method. STT(Standard Oil Synthetic Zeolite-twenty-three) zeolite membranes perform well in He/CH4 separation due to their unique pore structure. However, intercrystalline defects are easily formed during hydrothermal synthesis and template removal, leading to a low selectivity of STT zeolite membrane at high pressure. Hence, these STT zeolite membranes cannot be directly used for helium extraction from natural gas. In order to mitigate these intercrystalline defects, a method by coating PDMS(polydimethylsiloxane) was proposed. The operating parameters such as PDMS content and curing temperature on the repair of intercrystalline defects were welloptimized to improve the He/CH4 selectivity. The PDMSmodified STT zeolite membranes were used to simulate helium extraction from the heliumdepleted natural gas containing 0.075% He. At the feed pressure of 5.2 MPa, the He/CH4 selectivity reached 166. In this case, the helium was enriched by 82fold and the helium recovery was 55%. The PDMSmodified STT zeolite membranes effectively eliminated the intercrystalline defects and enhanced the He/CH4 high pressure separation performance, showing the application prospects of modified STT zeolite membrane in helium extraction from heliumdepleted natural gas.