The embodiment of the invention provides a real-time monitoring method and system for four-dimensional geometric features of oil and gas fracturing cracks. The method comprises the steps that pseudo-random electromagnetic waves are used for exciting a fracturing target area, the correlation between related macroscopic physical parameters and a microstructure of a fracturing layer is analyzed according to electric field airspace vector differential feedback of electromagnetic waves different in frequency before and after fracturing, an electromagnetic rock physical model of the fracturing layeris established, the crack length, crack height, crack width, reconstruction size and other geometric crack features of the cracks are clarified, and an interpretation template is established; fracturing of oil and gas resources can be efficiently, economically and effectively monitored in real time, electric field parameters of four dimensions (x, y, z, t) of the fracturing target area are obtained, and the fracturing effect on all fracturing sections of a fracturing well is evaluated. By means of the real-time monitoring method and system, the fracturing construction is effectively guided, the fracturing monitoring cost is greatly reduced, the fracturing monitoring effect is improved, the yield of a single well is increased, and the real-time monitoring method and system play an important role in the increase of the yield of the single well in the development process of the oil and gas resources in China.