The invention relates to the technical field of detection, in particular to an evaluation method for the black tea fermentation quality based on a near-infrared spectrum technology. The method comprises the following steps of preparation of black tea samples, collection of spectrum information, measurement of fermentation quality indexes, division of sample sets, pretreatment of spectrum information, screening of characteristic wavelength variables, establishment of a fermentation quality prediction model and prediction of all fermentation quality indexes. According to the evaluation method, sample pretreatment is simple, the fermentation quality can be accurately and quickly identified, the method is high in operability, and influence of subjective consciousness in artificial sensory organ evaluation and complex operation of a traditional chemical analysis method are avoided; the result is objective and accurate, the objectivity and accuracy of the black tea fermentation quality are improved, the theoretical basis is provided for further implementation of an automatic, intelligent and precise fermentation control technology, and the method has great realistic significance and application prospects in detection of tea quality indexes.