The invention discloses a modified 
maltose syrup 
retarder as well as a preparation method and application thereof. The modified 
maltose syrup 
retarder is prepared from 
maltose syrup, 
acrylic acid, an activating agent, unsaturated acid, esters, 
acrylamide, an initiator, deionized water and liquid caustic soda in a 
mass part ratio of (79-157):(10-40):(0.5-3.2):(40-80):(20-40):(20-40):(1-5):(500-750):(8-15). The preparation method comprises the following steps: putting malt syrup and 
acrylic acid into a No.1 reaction kettle according to the 
mass part ratio of (4-8):1, further adding an activating agent which is 0.5-2% of the total amount of the malt syrup, heating to 70-90 DEG C, stirring and reacting for 4 hours, and cooling to 
room temperature to obtain an 
intermediate product A; then adding the 
intermediate product A, unsaturated acid, esters, 
acrylamide, an initiator and deionized water in a 
mass ratio of (100-200):(40-80):(20-40):(20-40):(1-5):(500-750) into a No.2 reaction kettle, heating to 85-90 DEG C, stirring the mixture to react for 4 hours, cooling a 
reaction product to 
room temperature, and regulating the pH value to be about 7 by using liquid caustic soda to obtain the modified malt syrup 
retarder.