Abstract: The GNSS water vapor tomography technique can be used to obtain spatially resolved humidity information about the troposphere. The application of this method in GNSS water vapor tomography is discussed in detail considering the need to save computer memory and in light of the high stability when calculating inversion with the algebraic reconstruction technique, The Algebraic Reconstruction Technique is used to construct the distribution of water vapor; experimental results indicate that the solution of the traditional ART shows large reconstruction error due to the distribution property of the water vapor in the troposphere, while the IART method which adapts a relaxation parameter vector gets a favorable solution. The MART method also shows the similar results. Compared inversion with constraints, the algebraic reconstruction technique method is more susceptible to the observation error. The solution generated by the MART method is better than that of the IART method.