The invention discloses a low-noise air pump which comprises an upper cover, a cylinder, a piston, a base, a unidirectional inlet and outlet air distributing device, a motor, a linkage mechanism and a partition plate. The upper cover is provided with an exhaust port and an air inlet, and the piston is integrally provided with at least two air bags; the partition plate is provided with a first air outlet hole and first air inlet holes; the partition plate is fixed to a position between the upper cover and the unidirectional inlet and outlet air distributing device, the partition plate and the upper cover are hermetically matched with each other to form a sealed cavity, the air inlet of the upper cover and the first air inlet holes of the partition plate are respectively communicated with the sealed cavity, the first air outlet hole of the partition plate is communicated with the exhaust port of the upper cover, and the first air outlet hole and the first air inlet holes are respectively correspondingly matched with the unidirectional inlet and outlet air distributing device to realize a unidirectional outlet air distributing effect and a unidirectional inlet air distributing effect. The low-noise air pump has the advantages that owing to the partition plate, an airflow passage is prolonged, inlet air can be buffered, impact force is reduced, accordingly, running noise of the air pump is greatly reduced, and tilting deformation of an air inlet check valve of the unidirectional inlet and outlet air distributing device due to long-term direct stress can be prevented.