Abstract: Shallow micro targets in the seabed are generally small in size and shallow in burial depth, and due to the particularity of their materials, the current application of underwater acoustic detection methods cannot achieve good detection effects. From the perspective of seismic acoustic numerical simulation, this paper studies how to achieve high-precision detection of small targets in the shallow seabed by multi-channel seismic acoustic detection. Firstly, the high-order staggered grid finite difference method based on wave theory realizes the forward modeling of small targets, explores the seismic acoustic propagation response characteristics of shallow sea micro targets under different main frequencies, different seabed morphologies, and different burial conditions, and summarizes the propagation laws of small targets under different conditions. Furthermore, the reverse time migration technology with higher imaging accuracy realizes high-precision imaging of the position and morphology of small targets. The trial results of different shallow water micro targets models show that the multi-channel seismic acoustic detection method can achieve high-precision detection of shallow water micro target bodies, and the detected small targets have accurate imaging position and good shape characterization.