Welcome to ICCTIT 2021 2021 International Conference on Communication Technology and Information Technology (ICCTIT 2021) will be held in Harbin, China during December 3-5, 2021. The conference is an international conference for the presentation of technological advances and research results in the fields of Communication Technology and Information Technology. ICCTIT 2021 also sets up 3 Academic Sub-Forum, there are "Wireless Network and Communication Technology Forum", "Network Physical System Integration and Human-Computer Interaction Forum", "Distributed Network and Intelligent Interconnection Forum". The conference will bring together leading researchers, engineers and scientists in the domain of interest from around the world. We warmly welcome previous and prospected authors submit your new research papers to ICCTIT 2021, and share the valuable experiences with the scientist and scholars around the world.