Abstract: The Internet has become a critical infrastructures in modern society, in which transmission performance directly determines the capability and value of the services it carries. With the rapid development of mobile and interactive Internet applications, low-latency transmission in large-scale Internet faces three technical challenges at the application layer, transport layer, and network layer: the mismatch between dynamic sending decisions of application data and available network resources, the incoordination between network transmission decisions and changes in network status, and the inconsistency between differentiated services and the processing logic of network devices. To address the bottlenecks of traditional hierarchical and single-point transmission optimization, this paper proposes and constructs a collaborative transmission technology system for large-scale Internet services. It introduces the technological achievements within this system in three aspects: intelligent transmission decision-making for applications, multi-dimensional collaborative transmission, and customized in-network transmission acceleration, including key insights, basic ideas and principles, and results of large-scale deployment. Finally, the next development trends of Internet transmission technology are prospected.