Phytoremediation is a green and attractive technique for remediating heavy metal pollution. Understanding the distribution of heavy metals in different plant parts can provide insight into the molecular mechanisms of heavy metal phytoremediation. Laser-induced breakdown spectroscopy (LIBS) has outstanding technical advantages for the rapid in situ analysis of elements, especially for the direct analysis of solid samples without complex sample pre-treatment. Elemental scanning imaging is currently an important research and application direction of LIBS technology. A nanosecond pulsed laser-based elemental imaging LIBS device was developed with a spot resolution of 50 μm, a sample movement step of 100 μm and an imaging analysis speed of 6.25 mm2·min-1. The spectra of the target elements were normalized by baseline deduction, peak area fitting and normalization to produce a distribution thermogram with a pseudo-color representation of the elemental distribution in different regions of the sample. The in situ elemental imaging of pea plants was carried out using a hydroponic model, and the in situ elemental imaging of Ni, Cu, Cr and Pb were carried out using the imaging LIBS device. The results show that the device can effectively analyze the major matrix elements, such as C, Mg, Fe, Ca, Na and K, present in the plant and that after heavy metal stress, there is a significant accumulation of heavy metals in pea plants and different distribution trends of different heavy metals in the plant. Different from the distribution of nickel ions, the plant absorbed many copper ions and enriched it in the primordial root structures.The chromium accumulatedin the middle of the pea roots andin the germ and embryonic axis. However, large amounts of heavy metal lead was enrichedin the germ and embryonic axis, with the least amount in the root tip. This study shows that the elemental imaging LIBS technique enables the simultaneous in vivo analysis of multiple heavy metals in plants, which has implications for aiding the study of the mechanisms of phytoremediationin environmental waters. The imaging LIBS is a potential deviceand new method for related research in plant physiology and ecotoxicology.