A backflow-prevention oral irrigator, comprising a body (11), and a water storage tank (12) and an oral irrigating head (13) which are provided on the body (11). The body (11) is provided with a driving member (14) and a pump (15)； the driving member (14) is connected to a piston component (18)； the water storage tank (12) or the body (11) is provided with a water pipe (21) provided within the bump (15), and further comprises a valve block (22) and a duckbill valve (23)； the valve block (22) is provided with an elastic body (24) for shielding the water pipe (21)； the duckbill valve (23) is provided on the pump (15)； when the driving member (14) drives the piston component (18) to move along a direction away from the oral irrigating head (13), the duckbill valve (23) is closed, and the elastic body (24) of the valve block (22) is opened, to allow water in the water storage tank (12) to enter the pump (15)； when the driving member (14) drives the piston component (18) to move along a direction towards the oral irrigating head (13), the duckbill valve (23) is opened, and the elastic body (24) of the valve block (22) covers the water pipe (21), to spray water in the pump (15) out of the oral irrigating head (13) and prevent the water in the pump (15) from flowing back to the water storage tank, thereby improving the water spraying efficiency of the oral irrigator.L'invention concerne un irrigateur oral anti-refoulement, comprenant un corps (11), et un réservoir de stockage d'eau (12) et une tête d'irrigation buccale (13) qui sont disposés sur le corps (11). Le corps (11) est pourvu d'un élément d'entraînement (14) et d'une pompe (15)； l'élément d'entraînement (14) est relié à un composant piston (18)； le réservoir de stockage d'eau (12) ou le corps (11) est pourvu d'un tuyau d'eau (21) disposé à l'intérieur de la bosse (15), et comprend en outre un bloc de soupape (22) et une soupape en bec de canard (23)； le bloc de soupape (22) est pourvu d'un corps élastique (24) pou
