The invention provides a simulation experimental device and method for sediment particle deposition. Water absorption balls used for simulating sediment particles are added between two parallel glassboards in an experimental water tank, a power device is adopted to control the two parallel glass boards to swing left and right, the water absorption balls move along with swing of the glass boards,the stress environment in the sediment particle deposition process is simulated, and limitation to the time scale of sediment particle deposition principle study is broken through; and additionally, laser beams emitted by a laser device are processed through a transverse concave lens, a longitudinal short-focus concave lens, a longitudinal long-focus concave lens, a refractor and a triangular lensand then converted into sheet beams to irradiate the water absorption balls and tracer particles, a displacement image is obtained, water speed fields of water absorption ball gaps and displacement fields of the water absorption balls are obtained after processing, parasitic light of the sheet beams is reduced through optical paths, the image is clearer, and then the finally-obtained calculatingresult is more accurate.