Accurate, spatially explicit data on solum thickness (the vertical distance from the ground surface to the C horizon) is a critical missing link for Earth system modeling on the Qinghai-Tibet Plateau (QTP), where complex terrain and sparse subsurface observations limit the performance of traditional empirical mapping approaches. This study presents a new high-resolution (1 km) solum thickness dataset for the QTP developed using a revised geomorphic mass balance model. The model mechanistically couples climate-driven soil production with a multi-process erosion scheme that partitions sediment transport into hydraulic, aeolian, and gravitational components, while employing cluster-specific calibration and adjustable weighting coefficients to account for regional environmental heterogeneity. The resulting dataset reveals that solum thickness ranges from 0.39 to 2.04 m, with a plateau-wide mean of 0.89 m, exhibiting a pronounced decreasing gradient from the warm, humid southeast to the cold, arid northwest. Validation against 552 soil profile observations using 4-fold cross validation yields a Root Mean Square Error (RMSE) of 0.34 m and a Mean Relative Error of 0.78. This physically based approach achieves relative improvements of approximately 10 %-17 % in RMSE relative to existing national-scale products under shared observational constraints. Importantly, the model effectively reproduces realistic geomorphological patterns, such as sharp ridge-valley differentiation and elevation-dependent gradients that purely data-driven models often fail to capture in undersampled high-altitude regions. This dataset provides essential boundary conditions for hydrological, ecological, and cryospheric models, supporting more reliable assessments of the "Third Pole" under a changing climate. The dataset is available at figshare via 10.6084/m9.figshare.30925358 (Chen et al., 2025).