The invention discloses a method for preparing a plated piece for 210Po measurement. By improvement of a base material of the plated piece, paint material selection on the plated piece, a formula, a paint spraying process and a stamping process, finally various problems that the peeling and wrinkling of the plated piece occur due to poor paint adhesion, mutual adhesion occurs due to lacking of a paint spraying process, a surface needing no paint spraying is stained due to a wrong paint spraying process, wrinkling occurs due to wrong paint materials and paint spraying processes and burrs and unevenness occur due to stamping are solved. The pass rate of the plated piece is improved to 99% or above from less than 80%. The prepared plated piece does not need to undergo surface excitation and dirt removal through acid, a measurement process is simplified, and operation is facilitated.