An iron-zinc-plated steel plate with the yield strength of the 250-MPa level comprises, by weight percentage, 0.041-0.06% of C, 0.01-0.03% of Si, 0.34-0.50% of Mn, not larger than 0.02% of P, not larger than 0.015% of S, 0.015-0.05% of Als and not larger than 0.005% of N. A production method of the iron-zinc-plated steel plate with the yield strength of the 250-MPa level comprises the production steps that continuous hot dip galvanizing is conducted on the cold-rolled steel plate; the steel plate is conveyed to a zinc-iron diffusion treatment heating furnace under the heat preservation means; the zinc-plated steel plate is subjected to zinc-iron diffusion treatment at high temperature firstly and thereafter at low temperature; and the steel plate is naturally cooled to the room temperature for standby application. According to the iron-zinc-plated steel plate, on the premise of guaranteeing the use mechanics of the steel plate, the surface of a galvannealed coating is compact in structure and free of obvious micro-crack defects, zinc-iron grains on the surface of the coating are wee and evenly distributed in size, the coating is firmly combined with a steel base plate, and the pulverization and falling-off phenomena of the coating are not likely to happen in the stamping forming process.