Accurate dynamic models for the coupled heat and moisture transfer are important to simulate and predict the hygrothermal performance and to improve the indoor environment and structure durability. A comparison and comprehensive verification, i.e., including theoretical verification, inter-model verification and experimental verification, was performed on two models, the Künzel model and the Liu Chen model for the hygrothermal simulation of porous building envelopes, which are driven by relative humidity. The simulations were also carried out by two computation tools, self-programmed Fortran code and COMSOL Multiphysics for the two models. The verification showed that the simulation results of the two models agree well with the comparison values. Comparing the simulation results of the two models, it was found that the two models have little difference in the low relative humidity section in the hygroscopic range; while in the end of the hygroscopic range (relative humidity gradually increases to nearly 95%), the Künzel model can no longer accurately simulate the distributions of moisture. The investigations in this study demonstrate that the two models are accurate and applicable for hygrothermal simulations within the hygroscopic range and provide references for the verification of future hygrothermal models.