The invention discloses a seat surface defect detecting system based on machine vision. The seat surface defect detecting system comprises a mechanical arm, a numerical control device, a laser range finder, an image collecting device, an image processing and analyzing platform and a database system. The laser range finder and the image collecting device are installed on the mechanical arm; the numerical control device is connected with the mechanical arm; the image collecting device is connected with the image processing and analyzing platform; the image processing and analyzing platform is connected with the database system, and the database system is used for storing the detecting and analyzing result of the image processing and analyzing platform. Compared with the prior art, according to the seat surface defect detecting system, the product quality detection level is improved, the product quality detection efficiency is improved, the seat surface defect detecting system is beneficial supplement of intelligent industrial manufacturing, labor is released, and it is promoted that an enterprise uses the information technology to transform and improve traditional production flow; meanwhile, a single camera is adopted to replace multiple cameras so that the detection cost can be reduced; due to single-frame shooting, information processing pressure is reduced, and the system is simpler and more stable.