The invention provides a control method and device suitable for the foamed 
slag furnace condition in iron bath 
smelting reduction. The method includes the following steps that firstly, according to the changes of the secondary 
combustion rate of 
coal gas, the calorific value of 
coal gas, the semi-
coke content of 
smoke, the 
thermal load of a 
water cooled wall, the carbon content of molten iron, thecarbon 
powder content of 
slag, the 
slag density and the slag component index in iron bath 
smelting reduction production, whether foamed slag is generated or not is judged; secondly, if the foamed slag is generated, on the basis of existing production parameters, by increasing the ratio of the 
coal injection amount to the ore injection amount, the 
quaternary alkalinity of the slag is controlled to0.7-1.10, and the normal production of the furnace condition is recovered; and if the foamed slag is not generated, the production continues according to the existing production parameters. By meansof the method, accurate judgment of the foamed slag is achieved, rapid 
recovery of the normal production is achieved by controlling the production parameters, and the production efficiency is improved. By means of the method, the judgment basis and the 
recovery method of the the foamed slag furnace condition in iron bath 
smelting reduction are quantified, and the current blank of the production technology in the field is filled.