The utility model relates to a device for simulating settlement laws of a propping agent in a complex fracture network of volume fracturing. The device comprises a main crack formed by a fence, second-level cracks which are vertically connected with the main crack and three-level cracks which are parallel to the main crack and connected through the second-level cracks. An overall structure of the device can fully simulate different types of fracture networks of underground reservoirs to increase versatility of the device. Visualization of the device contributes to tracking and observation of experimental phenomena and recording of data to greatly improve the experiment efficiency, and further facilitates the maintenance of the device. Research results of an experiment carried out by using the device have certain reference values for theory researches of the volume fracturing and field applications.