Refrigeration type large-view-field medium-wave infrared optical system

The invention relates to a refrigeration type large-view-field medium-wave infrared optical system which comprises a front group A and a rear group B which are sequentially arranged in an optical pathdirection, wherein he front group A is sequentially provided with a meniscus positive lens A1, a meniscus positive lens A2 and a biconcave negative lens A3 along an incident light path, and the reargroup B is sequentially provided with a meniscus positive lens B1 and a meniscus positive lens B2 along the incident light path. The refrigeration type large-view-field medium-wave infrared optical system provided by the invention has a large field angle, can realize large-range scenery imaging, adopts a secondary imaging structural form, combines the first concave surface of the front group withthe bent object surface, can effectively compress the overall outer diameter size of the optical system while ensuring that the optical system realizes a large field, realizes miniaturization of the optical system, can be match