The utility model discloses a measuration water cushion pool bottom plate piece gap and move test device of water pressure, including the water cushion pool and pressure sensor, the water cushion pool includes that test section, bottom half and the test section upstream and downstream go-and-return of following the mobilizable box of water flow direction, bottom half form the non-test section of transverse joint respectively, is equipped with the welt between test section and the bottom half, forms end seam between welt and the test section, and pressure sensor passes the welt and gets into end seam. The utility model discloses not only can obtain the gap and move water pressure along horizontal distribution law, can also test the gap and move water pressure along fore-and-aft distribution law, the influence of moving the water pressure by the transverse joint and the longitudinal joint priming charge body to the gap has been taken all factors into consideration, consider not the uplift pressure of equidimension and moved the influence of water pressure to the gap, transverse joint or the longitudinal joint gap under different stagnant water destruction degree can be measured and the water pressure is moved, can simulate the deformation of concrete floor piece, more conform with actual engineering.