Presplit blasting method

The invention relates to a presplitting explosion method. A row of presplitting holes (3) with small diameters are drilled along designed excavation profile between the exploitation region and the boundary slope. Cushion holes (2) are designed parallel to the presplitting holes (3) and disposed between a main blast hole (1) and presplitting holes (3). The specific steps are as follows: a. determining parameters of the presplitting explosion holes, drilling; b. determining matched explosive load, loaded constitution, loaded ingredients, pack height and explosion initiation manner, implementing explosion. The invention is adaptive to explosion construction of highway cutting, large-scale hydropower station, metal mine exposed for long time. Integrality and stability of boundary rock mass are protected, occurrence of landslip is prevented, good and safe production environment is provided for mine, and good social efficiency and economic efficiency are provided.