The roll-over protective structure (ROPS) is a set of passive protective device installed on the cab of the engineering vehicle, which can provide effective protection for the driver in the roll-over accident. To solve contradictions between carrying capacity, rigidity, light weight and lateral endergonic effects of ROPS, topological optimization technology based on variable-density method has been introduced to ROPS design of heavy mining dumper, which can solve the problem of ROPS about optimal distribution of materials in a given design area and improve its lateral endergonic effect and vertical and parallel rigidity and reduce self weight. Firstly, the OptiStruct structure optimization module was used to make topology optimization design of ROPS. The optimization objective was to minimize the strain energy in multiple working conditions. Loads and constraints were applied according to the international standards. According to the topology optimization results, the detailed design was carried out. Afterwards, the dynamic analysis software LS-DYNA was used to make dynamic loading analysis for ROPS final design model. Finally, performance contrastive analysis between optimized ROPS and original ROPS was made. Results showed that the topology optimized ROPS did not invade DLV (deflection-limiting volume) under the three working conditions and met the international standards of carrying capacity requirements. The maximum energy absorption in lateral loading reached 175 kJ, which met the requirements of the international standards for the absorption of lateral energy. Compared with the original ROPS, the topology optimized ROPS reduced the load required for the lateral energy absorption from 1 324.5 kN to 1 231 kN. The vertical displacement of the loading center was reduced by 21.3% and the longitudinal displacement was reduced by 34.4%. Its quality was decreased by 24.1%. The research results provide a new method for the design of ROPS of heavy mining dumper, and the researching achievement has certain significance for the follow-up design and improvement of ROPS.