The invention provides a multi-scale seam net experimental device and an experimental method thereof. The device comprises a model main body frame, a digital partition plate, a digital grid, a mold pressing block and a displacement injection-production plug, the digital partition board divides the model main body frame into 22 mother areas (A1 to A11 and B1 to B11), 3 longitude areas (alpha1 to alpha3) and 10 latitude areas (beta1 to beta10), and each mother area is divided into four sub-areas (a, b, c and d) and a gamma net area by the digital grids; the device can realize simulation of a well pattern, a matrix, a hydraulic fracturing crack and a natural crack by filling natural rock cores or artificial rock cores into different areas according to actual oil reservoir conditions and integrally pouring the natural rock cores or artificial rock cores after pressing forming; further, saturation and pressure monitoring points are arranged in the primary area, the secondary area, the longitude area, the latitude area and the net area, so that the fluid state in the reservoir during oil reservoir exploitation can be dynamically monitored; based on the method, simulation of a big data multi-scale seam network model and pressure and saturation big data detection in a later experiment process can be realized.