The Low Earth Orbit (LEO) satellite mega-constellation based on Information Centric Networking (ICN) is a suitable network architecture to support Internet of Things (IoT), and the data naming is one of the basic problems in ICN. Concerning the requirements of transmission with low latency and data distribution with high throughput of IoT, a data naming mechanism of LEO satellite mega-constellation for IoT based on ICN was proposed. Firstly, a flat integrated structure fusing hierarchy, multi-component and Hash was adopted by the proposed data naming mechanism. Then, the prefix tags were used to describe hierarchical names to meet the need for fast multi-source retrieval of inner-network functions. Finally, a simulation platform of LEO satellite mega-constellation for IoT was designed and developed based on Network Simulator 3 (NS-3) to test the performance of the proposed data naming mechanism. The test and simulation results show that, compared with the traditional Internet Protocol (IP)-based system structure, the proposed data naming mechanism can provide higher Quality of Service (QoS) such as high throughput and low latency to LEO satellite mega-constellation for IoT.