The invention discloses an automatic drill-pipe column selection control system for a horizontal directional drilling machine. The automatic drill-pipe column selection control system for the horizontal directional drilling machine comprises a telescopic arm (3), a telescopic arm run switch (S5), a switch part (K), a magnetic valve (Y2), a telescopic arm support (4), a mounting plate (1), a sensing steel plate (2), a drill-pipe column selection switch (S6), a first-column drill-pipe sensing switch (S1), a second-column drill-pipe sensing switch (S2), a third-column drill-pipe sensing switch (S3) and a fourth-column drill-pipe sensing switch (S4). According to the automatic drill-pipe column selection control system, drill pipes in the first column, the second column, the third column and the fourth column in a drill pipe box are selected automatically through the column selection switch arranged on an operating box and the sensing switches arranged on different positions of the side face of the telescopic arm of the drilling machine, labor intensity and risk of the drilling machine brought out when workers assemble and disassemble the drill pipes in the drill pipe box are avoided, thus safety in the drill pipe assembling and disassembling process is guaranteed, and working efficiency is improved as well.