An approach for hierarchical modeling and integrated model validation of complicated network software based on colored Petri nets (CP-net) is proposed to precisely describe the software's complicated functionalities and concurrent behaviors to improve the software's design and efficiency. Certain significant techniques for modeling, such as complex data abstraction, concurrency control and homogeneous entities modeling, are presented in detail, and the resolutions of function units generation and concurrent-equivalent model abstraction used for model validation are given. Besides, the proposed approach was applied to a specific network system as a representative to illustrate its usability and effectiveness. As there is few specific model validation methods discussed in literatures, this study contributes to a novel CP-net based integrated model validation approach with better feasibility. Validated software CP-net hierarchical models can specify complicated functionality and concurrent behaviors precisely for complex network software systems, and furthermore, they can be well used as fundamental formal models to promote the effectiveness and efficiency for the software verification or conformance testing technologies.