Floating guide shoe capable of completely closing fluid channel, central tubular column and well completion structure

The invention discloses a floating guide shoe capable of completely closing a fluid channel, a central pipe column and a well completion structure. The floating guide shoe comprises an outer shell, a guide shoe body and a check valve unit. The floating guide shoe further comprises a reverse closing unit, and when the reverse pressure difference between the inner cavity of the outer shell and the outer space of the floating guide shoe reaches or exceeds a second threshold value, the reverse closing unit is closed. The reverse closing unit is arranged, so that a fluid channel of the floating guide shoe can be completely closed, the situation that in the prior art, when the pressure of an inner cavity of the floating guide shoe is too large, a check valve unit automatically releases pressure is avoided, the reverse closing unit can be used in cooperation with a flow control screen pipe with the flow conductivity capable of being adjusted stage by stage, and the flow conductivity of the underground flow control s