Filling retaining wall is important guarantee to seal the filling slurry in the goaf to achieve the predetermined function.It is essential to study pressure variation rules of the filling retaining wall in the filling process.The paper starts with the physical simulation test and uses the filling retaining wall pressure test device to analyze the influence of filling density,filling height and dehydration on the pressure variation of filling the retaining wall during the filling process,and explore the pressure difference between the rapid filling and the actual filling.The dehydration of tailings slurry in the filling process has greater influence on the pressure variation of the retaining wall.The rules obtained from the simulation test results are consistent with the field test results,and can provide reference for the safe and economic design of the retaining wall.