Abstract: Breaking through the composite barriers in key core technologies is a necessary path to achieving technological self-reliance and strength. Based on the knowledge gap, path dependence and niche lock-in analytical framework, our paper systematically reveals the formation mechanisms of the triple barriers: Knowledge gap manifests as a dual imbalance between the fragmentation of explicit knowledge and the interruption in the inheritance of tacit knowledge. To break through it, a full-chain reconstruction mechanism is required, which includes the systematic integration of explicit knowledge, the explicit transformation of tacit knowledge, and the iterative optimization of knowledge systems; Path dependence arises from the self-solidification of technological systems, the synergistic lock-in of industrial chains, and the constraints of institutional combinations. To achieve trajectory transition, it is necessary to carry out modular decomposition of technical architectures, reconstruct technical standards, and design flexibly adjustable policy tools, among other measures. Niche Lock-in, in essence, refers to the multi-dimensional power solidification of technical standards, institutional rules, and knowledge networks. Achieving niche climbing relies on synergistic strategies including the reorganization of technical architectures, the remolding and integration of institutional rules, and the cognitive reconstruction of knowledge power. Furthermore, there exists a dynamic correlation between the triple barrier-breaking paths: knowledge reconstruction provides theoretical support for the leap of technological trajectories, the leap of technological trajectories creates interface conditions for niche ascension, and niche ascension feeds back to drive the innovation of knowledge production, thus forming a positive cycle that starts from knowledge reconstruction, moves to the leap of technological trajectories, then to niche ascension, and finally returns to knowledge reconstruction. Based on the above conclusions, the following implications are derived: ① Establish a knowledge factor transformation system to resolve the dilemma of tacit knowledge inheritance. A national industrial knowledge graph platform should be built to integrate multimodal perception technologies and systematically capture high-dimensional tacit knowledge. ② Innovate dynamic policy tools to address the dilemma of technological trajectory lock-in. It is necessary to design a special policy package for intergenerational technological leaps and embed a flexible buffer mechanism to cope with path dependence. ③ Implement an innovation ecosystem power restructuring project to break through standard nesting blockades. A technological standard upgrading plan should be launched, and a mechanism for transforming international rules on standard nesting should be established. ④ Improve the collaborative barrier-breaking mechanism to enhance systematic evolution capability. An industry-university-research-government collaborative platform covering barrier diagnosis, path adaptation, and innovation ecosystem restructuring should be constructed, and a real-time monitoring indicator system for the three types of barriers should be developed.