Provided are a method and device for authenticating an identity based on fusion of multiple biological characteristics. The method includes: collecting at least two types of biological characteristic identity information of a to-be-identified user; performing characteristic extraction on each type of the collected biological characteristic identify information, to obtain characteristic information corresponding to the type; establishing characteristic matrixes based on the characteristic information; performing normalization processing on each of the characteristic matrixes; performing dynamic weighting fusion on all of the normalized characteristic matrixes, to obtain a fused characteristic matrix; matching the fused characteristic matrix with a preset standard matrix, to obtain a matching score; and obtaining an identity identification result of the to-be-identified user based on a Bayesian decision model and the matching score.