The maximum amplification speed within 1 kb can reach 1 sec/kb, greatly saving reaction time. The pre-prepared 2 × Master Mix only needs to add primers and templates to perform amplification, which reduces pipetting operations and improves detection throughput and results reproducibility. The kit has excellent amplification performance and high storage stability. It is suitable for PCR amplification within 5 kb using genome as template and PCR amplification within 10 kb using plasmid and λDNA as template. The protective agent added to the system allows 2 × Master Mix to maintain stable activity after repeated freeze and thaw. Premixed with green loading dye, which can be directly load into electrophoresis gel after PCR. The PCR product has an adenine at the 3' end, which can be directly cloned into T vectors and is suitable for ClonExpress, TA-cloning kits and TOPO cloning kits (Vazyme #C115/C116/C311/C602).