The invention provides a design method of a cement stabilized iron tailing sand base course material and relates to a design method of a base course material, aiming at solving the problem that a traditional design method of the cement stabilized iron tailing sand base course material cannot meet the design of the cement stabilized iron tailing sand base course material. The design method comprises the following steps: 1: determining an utilization range of deign parameters; 2: measuring 7-day unconfined compressive strength of each group of test in a central composite design test table; 3: obtaining a ternary quadratic fitting equation; 4: obtaining optimal ranges of fineness modulus of iron tailing sand, utilization amount of the iron tailing sand and utilization amount of a cement binding material; 5: selecting three stone material gradations through single-gear gradation adjustment; 6: selecting a maximal stone material gradation with the 7-day unconfined compressive strength as anoptimal gradation; 7: measuring the optimal moisture content and the maximum dry density of a standard compaction test part under different cement utilization amounts; 8: determining an optimal cement utilization amount; 9: preparing a test part and carrying out freezing resistance identification on the test part. The design method provided by the invention is used for the technical field of roadengineering materials.