The invention relates to a method for arranging a rock plug for a rock plug exploding model test, relates to a rock plug arranging method in a hydraulic model test, especially, in a water inlet rock plug exploding model test for a power station modification project, and belongs to the field of a water conservancy project model test. The method is characterized by comprising the following steps: firstly, establishing a normality model according to the size of a rock plug exploding model, wherein the model specifically comprises a water reservoir, a rock plug water inlet, a water diversion section and a gate shaft, and the water reservoir is made by welding 4mm steel plates with a steel frame; for facilitating measuring and controlling on inner stacked residue pressure and top cavity pressure of a residue collecting pit and flowing water acting force, adopting one steel plate for preparing one side of the water inlet of a water reservoir slope; arranging an inclined angle between a mountain surface and the water level as Ah, thereby forming the inclined angle between the steel plate on one side of the water inlet of the water reservoir slope and the water level at (Ah-3) degrees; utilizing cement mortar to form terrain on the water inlet side of the water reservoir on the steel plate. The invention provides the method for arranging the rock plug for the rock plug exploding model test and the method for reasonably arranging the model rock plug padding and rock plug cork base and reasonably arranging a detonator. The method provided by the invention is reliable and the simulation is accurate and reasonable.