The invention discloses a converter transformer casing and T-connected tubular bus-bar sliding connection over-current fitting for converter stations, which includes an over-current fitting component,an adjustable connecting ball rod component, and a slide slot and ball socket fitting component. The two ends of the over-current fitting component are respectively used for being connected with a converter transformer casing and a T-connected tubular bus-bar. The adjustable connecting ball rod component consists of a rod body A and a rod body B, the rod body B is sheathed in the rod body A, andthe rod body can move along the axis of the rod body A. The free end of the rod body A is connected with the end, connected with the converter transformer casing, of the over-current fitting component. The free end of the rod body B is hinged to a ball head. The slide slot and ball socket fitting component includes a slide slot and ball socket fitting body. The slide slot and ball socket fitting body is provided with a ball socket on one end face thereof and a slide slot on the other end face thereof. The ball head matches the ball socket. The slide slot is connected with the end, connected with the T-connected tubular bus-bar, of the over-current fitting component through a bolt. One end of the fitting is installed on the converter transformer casing to realize over-current and mechanicalconnection.