The invention relates to the technical field of ship manufacturing, in particular to a fixed ballast of a cement steel sand mixture, which comprises cement, fresh water and steel shot. Cement, steel shot and water are evenly mixed and stirred in a certain proportion and then filled into an empty cabin at the bottom of the ship in time. The fixed ballast of the cement steel shot mixture has the advantages that 1.the density and the strength of the cement steel shot mixture are heavier than those of the pure dry cement; with heavy density, the effect of improving the stability of ships is more obvious with low center of gravity of ships; with high strength, the structure of ship hull can be well protected and meanwhile the partial strength of ship hull can be increased. 2. cement, water andsteel shot belong to fluid when they are just mixed, so that the mixture can be used for irrigating and filling devices and applied to narrow empty cabin which is hard for the construction staff to enter into. 3. lower cost of design and construction are convenient to product and fill the empty cabin of ships, which improves efficiency and saves the period of ship manufacturing. 4. long-term maintenance is no need for the fixed ballast. 5. the fixing method of the fixed ballast is fastening and reliable.