Needleless connecting piece shell structure

A needleless connecting piece shell structure comprises a shell body, the top of the shell body is provided with an upper connector, the bottom of the shell body is provided with a lower connector used for being matched with a base, a cavity facilitating capsule installation is formed in the shell body, and the side portion of one side of the shell body is provided with a side connector used for being matched with a heparin cap. A cavity is formed in the shell body, an opening is formed in the side portion of one side of the cavity, the side connector is communicated with the cavity through the opening, an upper blocking part extending downwards is arranged on the shell body at the top of the opening, a lower blocking part extending upwards is arranged on the shell body at the bottom of the opening, and a gap facilitating liquid circulation is reserved between the upper blocking part and the lower blocking part. The needle-free connecting piece is reasonable in design, it can be ensured that when an injection