The invention relates to the field of anti-seismic railway bridges, in particular to a seismic mitigation and absorption support base for a bridge. The support base comprises a support base main body, a limiting device and a speed locker, wherein the support base main body comprises an upper support base plate, a spherical crown lining plate, a lower support base plate and a base plate; the spherical crown lining plate is located between the upper support base plate and the lower support base plate and is respectively in arc fit with the upper support base plate and the lower support base plate through a sliding component; a lower end face of the lower support base plate is matched with a sliding surface of the base plate through a guide rail component; the limiting device is fixedly connected with the upper support base plate; the two ends of a piston rod of the speed locker are respectively connected with the lower support base plate; a steel tube of the speed locker is fixedly connected with the base plate. The seismic mitigation and absorption support base for the bridge can release the temperature and load displacement in daily situation, ta he bridge body is not raised, and no additional force is generated; in earthquake, the locker is locked, and the seismic mitigation and absorption support base plays a role in seismic mitigation and absorption; a reliable limiting device is arranged on the seismic mitigation and absorption support base, so that the limiting requirement is met while the rotation of the support base is not influenced.