The invention discloses a compound inoculant used for producing D-type graphite cast iron, which is characterized in that the weight percents of the constituents are as follows: magnesium 1.0-4.0, rare earth 4.0-8.0, titanium 4.0-9.0, aluminum 1.5-3.0, stibium 0.5-2.0, calcium 2.0-5.0, barium 1.0-4.0, silicon 35-50 and the balance of iron. When the compound inoculant is employed to carry out inoculation on the melted iron with high carbon equivalent, the obtained graphite in the cast iron is the D-type graphite. The mechanical properties of castings are high, the tensile strength reaches over 250MPa and the compactness is good. The melted iron has high carbon equivalent, thus greatly improving the casting properties of alloys, reducing the residual stress of the castings, contributing to good size stability and enhancing the machinability of the castings. The multiple compound inoculant adopts ladle bottom pouring process, namely, the compound inoculant is placed on the bottom of a ladle, then the melted iron is injected and the compound inoculant is continuously melted and absorbed in the process of melted iron injection, thereby reaching the satisfactory inoculation effect, therefore, the method is simple and the use is convenient.