The invention provides a method and device for evaluating reservoir cap association welllogging, wherein the method comprises the following steps of: determining breakthrough pressure of a target shale cover layer according to the porosity of the target shale cover layer, and acquiring at least one auxiliary classification index corresponding to the target shale cover layer; determining the type of the target shale cover layer in a preset cover layer type library based on the breakthrough pressure and the auxiliary classification index of the target shale cover layer, wherein the cover layer type library is used for storing the corresponding relationship between each type of the cover layer and the breakthrough pressure and the auxiliary classification index; and combining the type of thetarget shale cover layer with a known evaluation result of the target reservoir covered by the target shale cover layer to obtain a comprehensive evaluation result aiming at the target reservoir. Theperformance classification of the shale cover layer can be accurately and effectively obtained, the storage conditions of the oil and gas reservoirs and the sealing performance of the oil and gas reservoirs can be combined with reservoir evaluation, the interpretation coincidence rate of welllogging evaluation can be effectively improved, and the accuracy of welllogging evaluation can be improved.