Disclosed is a blood pressure measuring instrument (300) and an air circuit structure thereof (100), and an air circuit box (10). The air circuit structure (100) comprises the air circuit box (10), an air charging pump (20), a cuff air nozzle (30), air release valves (60, 70) and an air pressure examination sensor (50). The air circuit box (10) comprises a shell (11) with a cavity (111) formed inside. An access port (1125), an air charging port (113) and air inlet ports (1183, 1191) are also separated and formed on the shell (11). The access port (1125), the air charging port (113) and the air inlet ports (1183, 1191) are all in communication with the cavity (111). The air charging pump (20) comprises an air charging interface (21) directly in communication with the air charging port (113). The cuff air nozzle (30) is directly in communication with the access port (1125). The air release valve (70) is arranged on the shell (11) and directly in communication with the air inlet ports (1183, 1191). The air pressure examination sensor (50) is directly in communication with the cavity (111) of the shell (11). The air circuit structure (100) makes the volume of the blood pressure measuring instrument (300) be relatively small and have a relatively high reliability.Linvention concerne un instrument de mesure de pression sanguine (300) et sa structure de circuit dair (100), et une boîte de circuit dair (10). La structure de circuit dair (100) comprend la boîte de circuit dair (10), une pompe dalimentation en air (20), une buse dair à manchon (30), des soupapes de libération dair (60, 70) et un capteur dexamen de pression dair (50). La boîte de circuit dair (10) comprend une coque (11) ayant une cavité (111) formée à lintérieur. Un orifice daccès (1125), un orifice dalimentation en air (113) et des orifices dentrée dair (1183, 1191) sont également séparés et formés sur la coque (11). Lorifice daccès (1125), lorifice dalimentation en air(113) et les orifices dentrée dair (118
