Disclosed is a disposable differential-pressure-type respiratory flow device, which is provided with a fixed pipe (10). The front and rear sections of the fixed pipe (10) are divided into a drainage section (11) and an engaging section (12). Two differential pressure measuring holes (121) are provided at front and rear portions of the engaging section (12). A pluggable mouthpiece (20) is attached to the engaging section (12) of the fixed pipe (10). A throttling element (24) is provided in the mouthpiece (20). Corresponding to the position of the two differential pressure measuring holes (121), two rows of pressure guide holes (211) arranged annularly and corresponding to the two pressure difference measuring holes (121) are provided in the front and rear of the throttling element (24). The throttling element (24) is interposed between the two rows of pressure guide holes (211). The above-mentioned respiratory flow device forms the throttling element (24) in the disposable mouthpiece (20), such that the specifications of the throttling element (24) can vary with different mouthpieces (20), and thus the measurement range is greater, and suitable for accurate measurement of respiratory flow data of users of various body types.La présente invention concerne un dispositif de flux respiratoire de type à pression différentielle jetable, qui est pourvu d'un tuyau fixe (10). Les sections avant et arrière du tuyau fixe (10) sont divisées en une section de drainage (11) et une section de prise (12). Deux trous de mesure de pression différentielle (121) sont prévus au niveau de parties avant et arrière de la section de prise (12). Un embout buccal enfichable (20) est fixé à la section de prise (12) du tuyau fixe (10). Un élément d'étranglement (24) est installé dans l'embout buccal (20). En fonction de la position des deux trous de mesure de pression différentielle (121), deux rangées de trous de guidage de pression (211) disposés de manière annulaire et correspondant aux deux
