The invention provides an in-section multi-cluster fracturing transformation nonlinear self degradation temporary plugging agent and a preparation method thereof. The in-section multi-cluster fracturing transformation nonlinear self degradation temporary plugging agent is prepared from the following substances in percentage by weight: 80 to 90 percent of body, 2 to 5 percent of initiators, 2 to 5percent of lubricating agents, 5 to 10 percent of shaping agents, 0.2 to 0.8 percent of enhancing agents and 1 to 3 percent of degradation accelerating agents, wherein the body is a mixture formed bypolyglycolide, polylactide-glycolide and polyvinyl alcohol; bonding cannot occur after the water meeting at the normal temperature; pumping injection is facilitated; the degradation in a limited timeis slow; the dissolution speed at the reservoir temperature and the time show the nonlinear relationship; the technical requirements of multi-cluster fracturing construction in the horizonal well section can be met; the micro expansion capability is realized; the intensity at the later plugging stage in a crack is improved; the slow degradation can also be realized under the condition of the medium environment change; the harm to the reservoir is small. Through the combination of an intermittent stirring reactor and a double-screw extruding machine, the influence of the temperature change of the production process on the temporary plugging agent product is improved; the product physical and chemical property index is more stable.