The invention provides an adaptor connector automatic assembly and detection device and an assembly and detection method thereof. The adaptor connector automatic assembly and detection device comprises a metal part feeding mechanism, an insulating part feeding mechanism, an assembly mechanism, a first detection mechanism, a second detection mechanism and a discharge detection mechanism which are arranged around a dividing plate, wherein the assembly mechanism comprises a shell nosing assembly and a dotting assembly. Compared with the prior art, through reasonable arrangement all working positions and mechanisms, the adaptor connector automatic assembly and detection device realizes stable assembly of metal parts and insulating parts through shell nosing and dotting; through detection of the height difference, the inner diameter and the dotting condition, the yield of products is ensured, and the assembly efficiency is improved; through reasonable arrangement of the discharge detectionmechanism, the adaptor connector automatic assembly and detection device can realize discharging of the products and detection of the assembly quality, achieves the functions of equipment and also reduces the occupied space of the equipment.