The effects of deviation distance from the focal spot to the target surface (d) on nanosecond-pulsed-laser drilling rates under different pulse energy were experimentally studied. The laser operated at a wavelength of 1.06 μm and pulse width of 10 ns (full width at half maximum). Pulse energy of 26, 52, 85, 204 and 274 mJ was used respectively. The drilling rate was measured under different pulse energy and d value. The experimental results show that d is one of the important aspects affecting laser drilling rate, and that it is a reasonable choice of using relatively low intensity laser pulses and d at +3～+4 mm. When d<0, the drilling rate is mainly determined by laser-induced thrermal ablation and shielding of plasma. And when d>0, the drilling rate is mainly determined by thermal ablation, shielding of plasma and promoting absorption induced by irradiation from the plasma at the beam waist.