Anti-refill bottle cap

A separate bottle cap comprising a bottle body connector, an outer cap, an anti-backflow assembly and an inner cap, wherein the bottle body connector is a hollow cylinder, a lower end thereof is fit and connected to a bottle body, the anti-backflow assembly is provided between the bottle body connector and the inner cap, a lower end of the outer cap is sleeved on the anti-backflow assembly and locks an inner wall of the bottle body connector, and the outer cap is provided on the inner cap;

• wherein:
• the anti-backflow assembly comprises a piston anti-backflow water blocking member and a water sealing connector, and the piston anti-backflow water blocking member is movably connected with the water sealing connector,
• a fluid passage is provided in the water sealing connector, and
• a cross three-dimensional bump is formed by the fluid passage and a piston anti-backflow water blocking member is configured to adaptively cover the cross-three dimensional bump.