The invention discloses a conservation measure auxiliary decision method specific for road disease causes. The method comprises the following steps: (1) making statistics according to expert questionnaire, and constructing a conservation measure applicable matrix A corresponding to the disease causes; (2) making statistics according to expert questionnaire, and constructing a specific matrix B of conservation measures to the disease causes; (3) making statistics according to expert questionnaire, and constructing a normalized vector h; (4) detecting according to field technology and constructing a disease cause generation vector w; (5) calculating conservation measure distribution probability p; (6) making conservation by selecting the conservation measure with the largest distribution probability. The method provided by the invention not only considers the applicability of the conservation measure to each disease cause, but also considers the specificity of the conservation measure to the disease cause, so that more efficiency of the conservation measure is applied on the existing disease cause.