The invention discloses a method for producing poly(pentabromobenzyl acrylate). The method comprises the following steps of: adding ethylene glycol monomethyl ether, acrylic acid, hydroquinone and anhydrous sodium carbonate into a reaction kettle; reacting at the temperature of between 35 DEG C and 45 DEG C until no bubbles are produced; heating to reach the temperature of between 100 DEG C and 120 DEG C; adding pentabromobenzyl bromide to react to obtain pentabromobenzyl acrylate; adding the ethylene glycol monomethyl ether and the prepared pentabromobenzyl acrylate into the reaction kettle;introducing nitrogen gas and stirring; heating to reach the temperature of between 90 DEG C and 110 DEG C; adding a mixed solution of dicumyl peroxide and glycol ether; polymerizing for 1.5 to 2.5 hours and then heating to reach the temperature of between 110 DEG C and 126 DEG C; and continuously reacting for 2 to 5 hours to prepare the poly(pentabromobenzyl acrylate). A product prepared by the method has the advantages of superior performance, no separation, no migration, extremely low influence on properties of materials, capability of increasing productivity, high mechanical property, highanti-ultraviolet stability and high thermal stability.