The invention discloses a method and device for quantitatively representing development characteristics of fractures in a rock stratum. The method comprises the steps that lithological well logging interpretation is carried out based on a well logging curve and an electrical imaging well logging image to obtain a lithological interpretation result along a depth direction; continuous same lithological points along the depth direction compose a single-layer lithological body to obtain the thickness of a single lithological body; the fractures are interpreted according to the characteristics of the electrical imaging well logging image, and the number of the fractures in each single lithological body is counted; the layer density of the fractures is determined according to the thickness of the single lithological body and the number of the fractures in the single lithological body; a fracture number cumulative frequency and a fracture frequency cumulative curve corresponding to the depthof a single rock stratum are generated based on the fracture number in the single lithological body; and quantitative representation is carried out on the development characteristics of the fracturesin the rock stratum based on the fracture layer density and the fracture frequency cumulative curve. The method and device for quantitatively representing the development characteristics of the fractures in the rock stratum can achieve the quantitative representation of the development characteristics of the fractures in the rock stratum.