Strontium atoms are widely used in quantum information and precision measurement, with their excited states 5s4d ³D_1,2,3 and 5s6s ³S₁ playing key roles in related experiments. However, existing key atomic parameters such as hyperfine structure constants and Landé-g factors are inconsistent, limiting further research. In this work, we employed the Multi-configuration Dirac-Hartree-Fock (MCDHF) method to systematically optimize the energy levels of the 5s5p ³P_0,1,2, 5s4d ³D_1,2,3, ¹D₂ and 5s6s ³S₁, ¹S₀ states for strontium, and focused on calculating the hyperfine structure constants (A and B) and Landé-g factors of the 5s4d ³D_1,2,3, ¹D₂, and 5s6s ³S₁ states. We comprehensively considered electronic correlation effects through an active space approach and multi-reference single and double excitations (MR-SD) method. The Breit interaction and quantum electrodynamics (QED) corrections were also included to improve calculation accuracy. Moreover, a rigorous uncertainty assessment was conducted in this work. Our results show that the magnetic dipole hyperfine structure constant A of the 5s4d ³D_1,2,3 triplet has a deviation of less than 3% from experimental values, while that of the 5s6s ³S₁ state is only 0.4%, significantly reducing the prior theory-experiment discrepancy, as shown in figure. Notably, we first reported the theoretical values of the electric quadrupole hyperfine structure constant B for the 5s4d ³D_1,2,3 states, which are in good agreement with experimental data, filling the theoretical gap. The Landé-g factor of the 5s4d ³D₁ state deviates by no more than 10^–4 from the experimental value, achieving higher precision than previous studies. Additionally, the calculated lifetimes of these states are consistent with most theoretical and experimental results. This work provides high-precision theoretical parameters for experiments related to strontium optical lattice clocks and quantum information, and verifies the reliability of the MCDHF method in studying highly excited atomic states, laying a foundation for further research on atomic structure and properties.