The utility model discloses a connection fitting and a fixing fitting. A dial wheel member inside a sleeve wall of a support member of the fixing fitting pushes outwards a pushing member, the pushing member then pushes contacts, and ultimately the fixing fitting is assembled in an expanding manner inside a tubular bus bar through the contacts. Before a fixing member is inserted into the tubular bus bar, inner end of the pushing member is disposed in a sunken groove on the dialing wheel member, and the contacts on the support member are not pushed up by the pushing member and are naturally closed so as to enable the whole fixing fitting to be conveniently inserted into a tube port of the tubular bus bar. After the whole fixing fitting is inserted into the tubular bus bar, the dial wheel member is rotated or pulled to enable the inner end of the pushing member to be moved from the sunken groove of the dial wheel member to the peripheral face, and the peripheral face of the dial wheel member pushes outwards the contacts through the pushing member so as to enable the fixing fitting to be assembled in an expanding manner inside the tubular bus bar. The connection fitting has the advantages of being convenient to assemble, simple in structure and small in occupied space.