The invention discloses a check valve, a container and an oral irrigator. The check valve is made of an elastic material and comprises a valve body part (1) with a hollow structure, wherein an opening communicated with the hollow structure is formed in the top of the valve body part (1), the valve body part (1) comprises two opposite connection walls (2) and two opposite membranes (3), two opposite sides of each connection wall (2) are respectively connected to the two membranes (3), the tops of the two membranes are away from each other, and the bottoms of the two membranes abut against each other. After the check valve is assembled on the container, the two membranes (3) with the bottoms abutting against each other block a connection channel between the hollow structure of the check valve and an inner cavity of the container to realize a leakage prevention function； and when the air pressure in the container is lower than the external atmospheric pressure, external air will burst the two members (3) to enable the bottoms of the two membranes (3) to move away from each other to unblock the connection channel between the hollow structure of the check valve and the inner cavity of the container, so that a ventilation function is realized. The check valve is simple in structure, easy to machine, low in production cost, small in size, good in structural stability and long in service life and occupies a small space.
