A system and method for specificity-based multimodality three-dimensional optical tomography imaging comprises steps of: optical imaging to obtain a light intensity of body surface optical signal of an imaging target CT imaging to obtain structure volume data establishing an equation representing a linear relationship between the distribution of the obtained light intensity of body surface optical signal of the imaging target, the obtained CT discrete mesh data and the distribution of unknown internal self-luminescence light sources establishing a dynamic sparse regularization target function in every iteration for the equation and reconstructing a tomography image. The present invention well considers the optical specificity of tissue, in which there is a non-uniform optical characteristic parameter distribution within the same tissue when finite element modeling is used, which is closer to the real situation, so that an accurate imaging effect is achieved.
