The key roles of the Marine Atmospheric Boundary Layer Height (MABLH) in pollution, climate, and model forecasting have long been recognized. The paper describes the vertical distribution of water vapour, heat, and matter in the atmosphere over the ocean. However, the observed MABLH has rarely been used to evaluate numerical weather prediction models. Therefore, we compare the temporal and spatial characteristics of the bias in the MABLH in the ocean predicted by the CMA-GFS model with Global Positioning System occultation data from 2019 to 2020. We find that: (1) The MABLH predicted by the CMA-GFS global model in the Western Pacific, South Pacific, and South Atlantic is reasonable. (2) There is an overestimation of the MABLH over the Intertropical Convergence Zone (ITCZ) and the South Pacific Convergence Zone (SPCZ). Preliminary analyses indicate that it may be due to the overestimation of the Lifting Condensation Level (LCL) by the Tropical deep Convection of the CMA-GFS model. (3) MABLH in the Southern Hemisphere Cumulus Region is underestimated by the CMA-GFS model, which may be due to inaccurate physical processes in the boundary layer parameterization. (4) There is an overestimation of the MABLH in a cloudy atmosphere, and the average bias is 200 m. The model forecast is more reasonable in a clear atmosphere, and ERA5 has a similar bias.