Bridge pier column replacement construction device and method

The invention particularly discloses a bridge pier column replacement construction device and method. Comprising the following steps that a settlement displacement observation point is arranged between a beam plate and a top tie beam, the settlement displacement observation point is used for obtaining deformation data between the beam plate and the top tie beam, and stability in the construction process is guaranteed according to the deformation data; a plurality of temporary supporting structures are uniformly arranged between the top straining beam and the ground; a plurality of brackets are arranged between the top straining beam and the beam plate; concrete of the beam plate support is broken and removed; the top straining beam is separated from the to-be-replaced pier column, and the to-be-replaced pier column is dismantled; a new pier column is built at the position of the pier column to be replaced; and the reinforcement cage erecting formwork, the support and the temporary supporting structure are dis