Abstract: High-low satellite-to-satellite tracking (SST-hl) and satellite gravity gradiometry (SGG) employed in GOCE mission are complementary in determining the Earth’s gravity field, but how to effectively use these two types of data is a key problem for the determination of optimal GOCE gravity filed solution. The least-squares spectral combination method for recovering the Earth’s gravity field from the combination of SST-hl and SGG data is studied. The spectral combination computing models and their error estimation formulae for combining disturbing potential T and radial gravity gradient Tzz data, and for combining disturbing potential T and gravity gradient combined components {Tzz-Txx-Tyy} data are established based on spherical harmonic analysis, respectively. Numerical simulation results indicate that the optimal combined solution can be obtained from the spectral combination computing model, which can effectively take into account the accuracy and spectral characteristics with each type of data. Finally, the feasibility and effectiveness of the spectral combination method is validated from GOCE real data processing. Two Earth’s gravity field models named WHU_GOCE_SC01S and WHU_GOCE_SC02S up to degree 180 are recovered from 61 days of GOCE data, the former is solved from T and Tzz, and the latter is solved from T and {Tzz-Txx-Tyy}. The results show that WHU_GOCE_SC02S model is more accurate than WHU_GOCE_SC01S model, and both of the models are more accurate than GOCE time-wise solution, and their total accuracy are most close to GOCE space-wise solution.