We developed a Python-based open-source software for scientific visualization of fluid dynamics datasets. This software is enabled by the VTK graphic rendering library and equipped with an interactive user interface built upon PyQt5. The concept of “scene module” is proposed to construct the rendered scene for graphic analysis. In the context of fluid dynamics, scene module is defined by associating a manifested geometry, such as a cut plane, an iso-surface, a set of streamlines and a vector field, with a set of visual attributes, including rendering scalar, colormap, and opacity. In the proposed framework, each scene module is processed by one single VTK pipeline, and a number of modules can be rendered simultaneously for multivariate graphic analysis. Beyond the VTK built-in functionality, additional implementation efforts are taken to enhance the annotating capability, improve the display of coordinate axes, and load input data of various formats. Two case studies are presented to demonstrate the capability of PyVT, especially the visualization of multivariate fluid dynamic datasets that typically possess complex and interdependent flow physics.