At present, China has not yet publicized the national calibration specification of respiratory tester, which makes it difficult to carry out the metrological traceability of various parameters of respiratory tester. Some self-compiled calibration methods for gas flow calibration have the problem that the flow calibration point is affected by the size of the plunger, which in turn limits the flow calibration range. To solve this problem, this paper proposes a calibration method based on the standard meter method and plunger method for static flow and tidal volume, respectively, and integrates two sets of pipelines and designs a calibration system. The basic principle of flow measurement of the ventilator detector is introduced, the calibration method is proposed based on this principle and the device is actually built and tested, and the test results show that the static flow measurement range of this system is 5~200 SLPM, with the extended uncertainty Ur(Qv)=0.602% (k=2); the tidal volume measurement range is 0~2 000 mL, with the extended uncertainty Ur(V)=0.174% (k=2), and the relative error meets the technical specifications, and this system can realize the calibration of respiratory tester calibration of flow parameters. The design of this calibration system lays the foundation for the research and development of the calibration device of respiratory tester and provides certain reference significance for the establishment of the calibration specification of respiratory tester.