Abstract: High-accuracy wind speed calibration under low-pressure conditions is a critical technical requirement for the development and environmental verification of Mars probes and stratospheric vehicles. To address the difficulty in evaluating wind speed calibration errors under such conditions, this study establishes a rotating flow field sliding-mesh model for the rotational calibration method and a submerged-jet wind speed model for the submerged-jet calibration method, and conducts simulations using computational fluid dynamics (CFD) methods. The results indicate that the primary error of the rotational calibration method is caused by gas entrainment. At a wind speed of 15 m/s, the entrainment-induced error can exceed 1.0 m/s. By applying a transient calibration strategy, the total error can be reduced to within 0.5 m/s. For the submerged-jet calibration method, the dominant error originates from non-uniform outlet velocity distributions under low-Reynolds-number conditions. When the wind speed is below 10 m/s, the calibration error is comparable to that of the rotational method. At wind speeds above 15 m/s, the calibration error gradually decreases as the uniform velocity region expands with increasing Reynolds number. The established simulation models and error evaluation methods can provide a reference for the thermal environment testing of Mars probes.