The invention discloses a high-precision pressure measuring system with variable reference pressure. The high-precision pressure measuring system is mainly used for wind tunnel experiment measurement,and belongs to the technical field of gas pressure measurement. The high-precision pressure measuring system provides reference pressure Pref which is close to measured pressure P through a referencepressure cavity, the reference pressure Pref is measured by means of a high-precision steady-state pressure meter, and a difference value dP between P and Pref is measured by using a small-measuring-range dynamic differential pressure sensor, namely, the measured pressure is decomposed into stable reference pressure and dynamic pressure with a small absolute value, and the stable reference pressure and the dynamic pressure are measured by means of appropriate sensors and then are re-synthesized. The high-precision pressure measuring system can satisfy requirements for response frequency of dynamic pressure measurement, has high measuring precision, solves the problem of low measurement precision of a high-frequency dynamic pressure sensor, and can adjust the reference pressure to adapt toa wide measuring range scope, so as to reduce the quantity demand of the sensors.