The invention discloses an APS-C telephoto lens for a digital mirrorless system camera. The APS-C telephoto lens sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens and a tenth lens from the object space, wherein the first lens is a spherical positive lens projected towards the object space, the second lens is a spherical positive lens projected towards the object space, the third lens is a spherical negative lens recessed towards the object space, the fourth lens is a spherical negative lens recessed towards the object space, the fifth lens is a spherical negative lens recessed towards the object space, the sixth lens is a spherical positive lens projected towards the object space, the seventh lens is a spherical positive lens projected towards the object space, the eighth lens is a spherical negative lens recessed towards the object space, the ninth lens is a spherical positive lens projected towards the object space, and the tenth lens is a spherical negative lens recessed towards the object space. The APS-C telephoto lens has the advantages that the large aperture design is adopted, the shutter speed is accelerated, and in addition, the cost performance is high.