Short-focus projection lens and projection imaging system

The utility model discloses a short-focus projection lens and a projection imaging system, and the short-focus projection lens comprises a lens assembly which comprises a plurality of spherical lenseswhich are arranged in the same optical axis, and is used for the projection imaging of an externally inputted light beam; the spherical lens comprises a first meniscus lens, a first biconvex lens, abiconcave lens, a second biconvex lens and a second meniscus lens which are sequentially arranged. According to the short-focus projection lens provided by the embodiment of the utility model, projection imaging can be carried out on an externally input light beam by selecting the plurality of coaxially arranged lenses, and the plurality of lenses are spherical lenses, so that the use of an aspheric lens can be avoided, and the technical problems of high processing difficulty and high cost of the aspheric lens adopted by the lens in the prior art can be solved. Moreover, the short-focus projection lens provided by the