Novel combined visible air blocking clean floor drain

The utility model discloses a novel combined visible air blocking clean floor drain. The device comprises a shell, an internal non-return device, an elbow part, a gasket, a chuck, a glass pressing ring and a glass sheet, the glass pressing ring is a cylindrical annular piece, the glass pressing ring comprises a buckling sealing section with the upper edge extending inwards and a chuck structure with the lower edge extending outwards, the internal non-return device is cylindrical, the upper portion of the internal non-return device is sealed, and a vertically-downward screw is arranged in the internal non-return device; a screw of the internal non-return device penetrates through a support nut of the lower discharge port of the shell, the height of the internal non-return device can be adjusted, the internal non-return device can be limited, an inlet in the left side of the shell is connected with a main pipe in a clamped mode, the lower discharge port of the shell is connected with a floor drain in a clamped