The invention discloses an air textured yarn terry detector comprising a yarn drum for winding an air textured yarn and a traction mechanism for driving the air textured yarn to advance; a left yarn guide for generating a clamping force on the air textured yarn and a right yarn guide for playing a guiding role for the air textured yarn are arranged between the yarn drum and the traction mechanism; a camera and a light source are mounted between the left yarn guide and the right yarn guide, and a magnifying glass is arranged below a lens of the camera; and the camera and a motor are connected with a computer provided with dedicated control software. The appearance condition of the air textured yarn is shot to form a picture through the coordination of the camera, the traction mechanism and the computer, so that location drifting and errors caused by moving strands and the camera by a hand can be avoided; meanwhile, by using the dedicated control software, a terry appearance picture captured by using the camera can be automatically analyzed and counted, the more and miscellaneous workload and personal errors caused by manual counting are reduced, and the air textured yarn terry detecting efficiency and accuracy are increased.