Presplit blasting serves as a fundamental technique for maintaining slope stability and ensuring contour precision during high-steep slope construction in open-pit mines. Conventional presplitting methods typically employ an axially spaced and radially decoupled charge configuration using detonating cords, bamboo spacers, and 32 mm emulsion explosives. Nevertheless, this conventional approach presents operational challenges including restricted borehole spacing, excessive drilling requirements, labor-intensive charge preparation, and inconsistent charging reliability. These operational deficiencies result in prolonged construction cycles, elevated project costs, and inconsistent half-hole preservation rates. To address these technical challenges, an innovative presplit blasting technique using standard PVC piping is developed for steep slope applications. The method involves 40~50 mm diameter PVC conduits with 115 mm blast holes to create precise decoupling spaces, followed by direct loading of 32 mm emulsion explosives into the pipes with 1~2 electronic detonators for initiation. Field validations were successfully conducted across multiple geological formations including quartz sandstone at Yingde, gneiss at Yangxi, granite dimension stone at Jieyang, and siltstone construction material deposits at Kaiping. The results demonstrate that: (1) The novel technique enables borehole spacing expansion to 2.0~2.2 m, achieving 33%~46% reduction in drilling consumption compared to traditional method; (2) Eliminating of complex construction components(detonating cords, bamboo spacers, and explosive rolls) reduces presplit blasting operation time by 47%; (3) Streamlined construction processes and material requirements yield approximately 42% lower overall costs; (4) Half-hole factor reached 65%~85% in soft rocks and 95% in hard rock formations, representing 5%~13% improvement over traditional techniques with enhanced effect stability. This methodology guarantees presplit blasting quality while simultaneously improving efficiency and cost-effectiveness, providing valuable guidance for analogous open-pit slope engineering projects.