The invention relates to a dilatation joint of a bridge, comprising a fixed seat (1) and a sliding seat (2) which are positioned at both sides of a commissure of the dilatation joint. The dilatation joint of the bridge is characterized in that the fixed seat (1) is fixed at one side of the commissure of the dilatation joint; the sliding seat (2) contacts the surface of the other side of the commissure (6) of the dilatation joint slidably; a connection plate (4) shielding the dilatation joint is arranged between the fixed seat (1) and the sliding seat (2); and both sides of the connection plate (4) are respectively articulated with the fixed seat (1) and the sliding seat (2). The dilatation joint is in an all-metal structure, has ageing resistance, can provide larger horizontal displacement amount, adopt the unique connection plate structure and realize vertical displacement and rotation displacement.