The invention discloses an automobile air dryer assembling and testing production line. At present, assembly of most of automobile air dryers at home is in a scattered operation state and a testing method is a manual intermittent partial testing method; however, selection and matching of the conventional assembling and testing equipment are not reasonable enough and poor in coordination; and therefore, the assembling process of the automobile air dryer is poor in smoothness and low in assembling and testing efficiency. The automobile air dryer assembling and testing production line comprises a U-shaped workbench line body, wherein the U-shaped workbench line body comprises six assembling workstations, two testing workstations and an assembling and testing workstation, namely a first workstation, a second workstation, a third workstation, a fourth workstation, a fifth workstation, a sixth workstation, a seventh workstation, an eighth workstation and a ninth workstation sequentially; the adjacent workstations are related to each other through a material conveying belt. A shell of the assembled and tested air dryer is transferred among the workstations through the material conveying belts between the workstations, working procedures are continuous, and the workstations are related through the material conveying belts, so that the assembling pace is ensured and the manufacturing cost is reduced.