The invention relates to a fracturing inclusion self-dissolving diversion agent and a preparation method thereof. The diversion agent is prepared by using 10-15 parts of guanidine collagen powder, 30-40 parts of ferric trichloride, 30-40 parts of alumina, 1-2 parts of sodium bicarbonate, 8-10 parts of ammonium persulfate, 1-2 parts of potassium ferricyanide and 1 part of gamma-aminopropyltriethoxysilane, has an inclusion form and is spherically granular in shape. The preparation method of the diversion agent comprises the following steps: sequentially dissolving the guanidine collagen powder, the ferric trichloride, the alumina, the sodium bicarbonate, the ammonium persulfate and the potassium ferricyanide in water according to above formula proportions at room temperature, stirring for 5min, carrying out drying caking of the above obtained solution, crushing, milling, spraying the surface of ammonium persulfate with the gamma-aminopropyltriethoxysilane coupling agent, wrapping the external layer of ammonium persulfate crystals by the above prepared powder to form spherical particles, and drying the particles to prepare the diversion agent. The diversion agent has a gel breaker inclusion form, has a self-dissolving capability, and does not need a gel breaking degradation agent in the construction.