Discloses is a low-noise dry-type iron core reactor assembling process. The assembling process includes the steps: S5-1, taking a flexible pouring guide pipe, blocking one end of the flexible pouring guide pipe, and uniformly drilling small holes in a section equal to the perimeter of an iron core column along a same side of the pouring guide pipe; S5-2, moving the iron core column down to enable a seam on the upper portion to be exposed; S5-3, enabling the pouring guide pipe to surround the seam by one circle, keeping the small holes to face the seam, and using a rubber belt to tension, wind and fix the pouring guide pipe; S5-4, hanging a coil up to enable a seam on the lower portion to be exposed; S5-5, burying the pouring guide pipe at the seam on the lower portion by referring to S5-3, and resetting an upper cushion block and a lower cushion block; S6, transferring a reactor into vacuum pouring equipment, and connecting the guide pipe; S7, vacuumizing to complete vacuum pouring of a seam of the iron core column and an iron yoke; S8, releasing vacuum, and transferring a reactor product into a curing furnace to complete resin curing of the seam. By the low-noise dry-type iron core reactor assembling process, vacuum pouring of the seam of the iron core column and the iron yoke of a dry-type iron core reactor can be realized, firmness in bonding and less proneness to loosening are realized, and seam noise is effectively inhibited.