The invention discloses a low-noise transformer and a manufacturing method thereof. The method comprises the steps that three parts of epoxy resin and two parts of polyamide are weighed according to the weight proportion and are prepared and stirred, so that a mixture is obtained; the end faces and junctures of a transformer iron core are coated with the mixture; the transformer iron core is placed at the room temperature for 24 hours and then dried, wherein the drying temperature is 80-100 DEG C, and the drying time is 2-3 hours. The noise of the transformer manufactured through the method can be effectively lowered by 1-2 decibels. As iron core binding belts are omitted, sleeving clearances of coils are effectively increased, the main insulation size of 10 kV low-voltage coils relative to the iron core is reduced by 2-3 mm, and the cost is lowered. Besides, the rigidity of the iron core is enhanced, foreign matters produced in the iron core machining process are effectively blocked, and therefore accidents are prevented.