External appearance defect examination method for circuit board

The invention provides a method used for testing the appearance defects of a circuit board, comprising the steps as follows: loading, collecting frontal images of the circuit board, collecting the reverse images of the circuit board, analyzing and sorting the images. The method can complete the appearance defect check on two surfaces of the circuit board extremely conveniently and quickly, can adopt a computer for automatic control, has quick check speed and high check efficiency, and can check the defects on the circuit board such as foreign matter, exposed copper, supplemented oil, scraping, poor gold-plating, character error, non-uniform green oil, non-uniform welding disc, non-uniform depth of channel, residual copper, omitted printing, developing and the like.