Earth and other planets deform under various forces. Numerical modeling is critical in understanding the nature of various dynamic deformation processes. This article introduces a newly developed open-source package, CitcomSVE-3.0, which efficiently solves the viscoelastic deformation of planetary bodies. We present benchmark results against a semi-analytical code. With its accuracy and efficiency, CitcomSVE-3.0 could advance research in planetary and climatic sciences.