Temporary plugging agent, preparation method and application thereof in oilfield exploitation

The present invention provides a temporary plugging agent preparation method, which comprises: A) mixing acrylamide and sodium alginate in water, sequentially adding a cross-linking agent and an initiator, and carrying out a polymerization reaction to obtain a sodium alginate/acrylamide hydrogel, wherein the cross-linking agent is one ore more of N,N-methylene bisacrylamide, N,N'-diallyl tartaric acid diamide, divinyl benzene, polyethylene glycol diacrylate and polyethylene glycol dimethacrylate, and the mass ratio of acrylamide to the cross-linking agent is 100: (0.01-1); and B) dipping the sodium alginate/acrylamide hydrogel obtained in the step A) in a zirconium salt solution, and drying to obtain the temporary plugging agent. According to the temporary plugging agent, the expansion multiple of the temporary plugging agent can be effectively reduced; and the swollen temporary plugging agent has high toughness and strength, and can achieve a better plugging effect on cracks. The invention further provides t