The invention discloses a negative pressure type soft infusion bag. According to the manufacturing process steps, material films of inner package bags are sterilized and are merged into a package workshop, the inner package bags are obtained after infusion valves are welded, the inner package bags are filled with liquid medicine, then soft infusion bags are formed, sterilized for the second time and then dried, light inspection is carried out for the first time, unqualified bags with packaging printing errors, welding errors and large impurities are removed, the soft infusion bags are sleeved with outer package bags, negative pressure is pumped between each outer package bag and the corresponding inner package bag, the bags are sterilized for the third time, boxed and placed in a storage to be stored temporarily, then light inspection is carried out for the second time, and leakage bags are removed. By the negative pressure type soft infusion bag, no bacterium can be left in an interlayer, large volume injection with micro-leakage of the inner package bag is conveniently and effectively removed, and the delivery liquid leakage rate is lowered to be below 0.029 per thousand.