Solution is an essential character for salt rocks. Pervasion is a liquid movement through porous media under the actions of solute concentration gradients，pressure gradients，or the both. As the difference of solution characters for different mineral components in calcium thenardite，the solution and pervasion mutual actions can be found in the calcium thenardite rock salt body under the action of certain osmotic pressure. Thus the calcium thenardite becomes penetrable porous medium，holding the pervasion and mechanical characteristics that are called solution pervasion and mechanical characteristics，respectively. It is greatly affected by the solubility of sodium sulfate，and one of the components is calcium thenardite. Experiments illustrate that the permeability is the function of solution time and osmotic pressure of calcium thenardite salt rock. Meanwhile，the three-dimensional mechanical characteristics of calcium thenardite salt rock take great changes after a period of solution pervasion actions. The compression strength of calcium thenardite rock salt changes from 46.53 MPa to 11.42 MPa after 49 h solution pervasion with 2.0 MPa confining pressure. Accordingly，the elastic modulus changes from 43.700 MPa to 0.834 MPa. So，it can be concluded that solution pervasion has great effect on mechanical characteristics of calcium thenardite rock salt.