The 2023 4th International Conference on Internet of Things, Artificial Intelligence and Mechanical Automation (IoTAIMA 2023) was held via hybrid form in Guangzhou, China during July 21st to 23rd, 2023, following the successes of previous events held in Hangzhou (2020, 2021), and Shanghai (2022). This year the IoTAIMA 2023 aimed to bring together researchers, developers, and users in both industry and academia in the world to discuss emerging issues on Internet of Things, artificial intelligence and mechanical automation, for sharing state-of-art results, and for exploring new areas of research and development.The Conference was organized by Peking University-Wuhan Institute for Artificial Intelligence and co-organized by Central South University School of Automation. More than 80 delegates from home and abroad attended the Conference.The IoTAIMA 2023 was featured with four keynote speeches (by Prof. Deyu Qi, Prof. Jinping Ao, Prof. Ming Jiang, Assoc. Prof. Wei Wei, respectively), and several oral and poster presentations, in which a wide range of topics were covered and the most recent significant results were presented. Prof. Ming Jiang from Sun Yat-sen University, China addressed his speech Massive MIMO Aided Multinetwork 3D Positioning. Exploiting a distributed M-MIMO framework, his team proposed to employ a deep belief network (DBN) to analyze the received signal strengths (RSS) generated by a diffraction model. Next, the preliminary DBN estimates were forwarded to a long-short term memory network (LSTMN), where the trajectory information of the targeted UE can be extracted based on much less historical trajectory information than existing solutions. Then, the three-dimension (3D) coordinates of the UE’s positions can be estimated with a back propagation neural network (BPNN) which combines the outputs of DBN and LSTMN. Finally, extensive simulation results were provided to demonstrate the effectiveness of the proposed BPNN scheme.Quantities of excellent papers evaluated based on their originality, technical or research content, correctness, relevance to conference, contributions, and readability were presented in the Conference Proceedings published by Journal of Physics: Conference Series (JPCS). The topics of these papers include Radio Frequency Identification, Micro-Electro-Mechanical Systems, New Sensing Technology, Unmanned System Control Technology, Industrial Robots and Automatic Production line, etc.With the excellent quality of all the presentations, the IoTAIMA 2023 was a great success. We wish to thank the sponsors of the Conference, and particularly the Technical Program Committee. We would also like to extend our gratitude to all the speakers and authors for sharing scientific ideas and presenting new perspectives with us on related topics. Our appreciation also goes to the editors and other staff of JPCS for the assistance it provided for the publication of this paper volume.The Committee of IoTAIMA 2023List of Committee Member is available in this Pdf.