Single pulses exported from Nd: YAG laser are used to act on the same position of soil sample surface repeatedly to form laser- induced craters. Grating spectrometer and ICCD are used to record plasma emission spectra generated from each laser pulse. The effect of laser-induced craters on radiation characteristics of soil plasma is investigated. The experimental results show that there exists a trend that the line intensity and signalto- background ratio of Cr and Pb elements initially increase and then decrease along with increased number of laser shots under the confinement effect of crater walls. Overall, the best signal intensity can be obtained with a confinement laser-induced crater with 1.0 mm diameter and 2.5 mm depth. The experiment clearly indicates that self-absorption becomes weaker and then disappears along with increased number of laser shots. The results show that the line intensity and signal-to-background ratio are both improved and the electron temperature increases under the confinement effect of the crater walls, reducing the level of self-absorption spectral lines effectively.