2D Space Time Tracer is a visualization and analysis system designed specifically for joint observation of "space time" in a two-dimensional plane. It integrates high-speed image acquisition, sub-pixel trajectory extraction, and real-time spatiotemporal rendering into a portable instrument, allowing users to "see" and quantify the complete spatiotemporal evolution process of any moving target in a two-dimensional plane within 30 seconds. Typical applications: Microfluidic chips: cell/droplet trajectories, mixing efficiency evaluation; Robot vision: verification of planar positioning accuracy and path repeatability; Educational demonstration: Reynolds experiment, wave propagation, real-time visualization of harmonic motion; Industrial quality inspection: flying posture of ink droplets in inkjet print heads and movement of vibrating screen particles.