The invention particularly discloses a board appearance quality comprehensive quantitative evaluation method. The method solves the problems that existing board appearance quality evaluation is not accurate and low in efficiency, and online detection and evaluation are difficult to achieve. The board appearance quality comprehensive quantitative evaluation method includes the following steps that a board image is acquired, characteristic parameters of board appearance quality are measured, a knot influence coefficient h, a crack position influence coefficient k and a crack length influence coefficient p are constructed, a board appearance quality comprehensive quantitative evaluation measure value Q is determined accordingly, and Q is divided into four grades to define boards with different qualities. By means of the method, the defect that a traditional board appearance quality comprehensive quantitative evaluation method is too subjective or evaluation is not accurate due to too many influence factors is overcome, the board appearance quality comprehensive quantitative evaluation method can be applied to a wider range of fields, and a novel board appearance quality evaluation system can be constructed in combination with a computer image processing method and the like.