A tube cutting device with a rapid separable handle comprises a tube cutter and a handle. The tube cutter comprises a C-shaped housing, a one-way rotation part, and a limit part. The handle comprises a grip part, a C-shaped guiding seat, a separation control part, and a control button. The C-shaped guiding seat is for unidirectional rotation of the C-shaped housing via the one-way rotation part. In a combination position, it engages with the limit part so that the tube cutter and the handle are mutually fixed. In a separation position, it is separated from the limit part so that the tube cutter and the handle are separable from each other for independently perform tube cutting.