The invention discloses a keyword classifying method and a keyword classifying device. The keyword classifying method comprises the following steps: dividing a keyword to obtain morphological components of the keyword; extracting a plurality of morphological elements from the morphological components; inquiring a preset class to which each morphological element belongs so as to obtain a plurality of attribution classes; calculating the probability of each attribution class so as to obtain a plurality of attribution probabilities; determining the class represented by the maximum probability in the attribution probabilities as the class of the keyword. Through the keyword classifying method and the keyword classifying device, the problem that in the prior art, the precision for determining the class of the keyword is relatively low is solved, so that the effect of improving the accuracy for determining the class of the keyword is further realized.