The present invention discloses a device and method of test for simulation of deep-lying tunnel blasting excavation unloading. The device comprises model frame outer frames, a model frame inner frame,a front side plate, a back side plate, a model sample, a bearing plate, hydraulic jacks, a high-pressure oil pump, a pressure tube, a dynamic test analyzer, a dynamic strain indicator, a statical strain indicator, a blasting vibration monitoring instrument, a computer, a speed sensor, miniature pressure boxes, resistance strain sheets, a wire, an exploder, a shot hole and a cartridge. The test method comprises the following steps of: the step 1, manufacturing of the model sample; the step 2, installation of the model sample; the step 3, loading of the model sample; the step 4, simulation of blasting excavation and data collection; and the step 5, data processing and analysis. The device and method of test for simulation of deep-lying tunnel blasting excavation unloading can perform good recovery of a tunnel geological environment according to a certain similarity and according to actual geological data through a similar material simulation test, are low in cost and convenient to operate, and can reflect a general rule of surrounding rock deformation and destroying.