The extensometric data observed at Geodynamic Observatory Ningqiang are strongly disturbed by barometric pressure variations in the high-frequency band since 2011. Although this phenonmenon has been observed for many years,the frequency-dependent barometric responses of extensometers are still not well understood. For this reason,we systematically analyze the coherences and transfer functions of tunnel strain changes associated with barometric pressure for Ningqiang observatory,respectively. In the data analysis,the 92-d-long data set of tunnel strain and barometric pressure data from 1st January to 2nd April 2019 are utilized. The results show that the atmospheric response of Ningqiang observatory obviously depends on frequency in the high-frequency range(8～40 cpd),and the barometric pressure coefficient and the phase advance can reach up to 7.80×10^-9/hPa and 108.27°,respectively. Besides,the responses of NS and EW components in the extensometers are slightly different. In summary,our work not only provides a useful method for frequency-dependent pressure correction in the high-frequency band,but also offers profound insights to study the mechanism of the pressure-induced noise from extensometric records.