A dental suction assisting device, comprising: an upper molar seat located at an upper portion of a body made of a soft material, and having anti-separation protrusions arranged at a regular interval and a space for allowing seating of upper molars; a lower molar seat located at a lower portion of the body, and having anti-separation protrusions arranged at a regular interval and a space for allowing seating of lower molars; a fastening portion having an insertion hole and a through-hole formed between the upper molar seat and the lower molar seat, and protruding outward from a side of the insertion hole so as to allow fastening of a suction tube; a suction port formed at a position opposite to the fastening portion, having a first suction hole formed therein to be connected to the through-hole, and protruding outward so as to allow secretions including saliva secreted into an oral cavity to be sucked through the suction tube; a leg formed at each of opposite sides of the lower molar seat, and configured such that the respective legs are brought into intimate contact with opposite side surfaces of the lower molars, the leg having partitions arranged at a regular interval; and a wing extending from a side of the leg, and seated between the lower molars and skin in the oral cavity, wherein the wing comprises: a second protrusion formed in the same direction as the partitions; and a third protrusion formed at a corner of the wing; and a gap is formed between the second protrusion and the third protrusion, and the secretions are sucked through the gap. an upper molar seat located at an upper portion of a body made of a soft material, and having anti-separation protrusions arranged at a regular interval and a space for allowing seating of upper molars; a lower molar seat located at a lower portion of the body, and having anti-separation protrusions arranged at a regular interval and a space for allowing seating of lower molars; a fastening portion having an insertion hole and a through-hole formed between the upper molar seat and the lower molar seat, and protruding outward from a side of the insertion hole so as to allow fastening of a suction tube; a suction port formed at a position opposite to the fastening portion, having a first suction hole formed therein to be connected to the through-hole, and protruding outward so as to allow secretions including saliva secreted into an oral cavity to be sucked through the suction tube; a leg formed at each of opposite sides of the lower molar seat, and configured such that the respective legs are brought into intimate contact with opposite side surfaces of the lower molars, the leg having partitions arranged at a regular interval; and a wing extending from a side of the leg, and seated between the lower molars and skin in the oral cavity, wherein the wing comprises: a second protrusion formed in the same direction as the partitions; and a third protrusion formed at a corner of the wing; and a gap is formed between the second protrusion and the third protrusion, and the secretions are sucked through the gap. a second protrusion formed in the same direction as the partitions; and a third protrusion formed at a corner of the wing; and a gap is formed between the second protrusion and the third protrusion, and the secretions are sucked through the gap.