To improve the gelation of soy protein isolate， microwave technology was introduced into its production process. Traditional water bath heating treatment (90 ℃， 15 min) was used as the control group to explore the effects of different treatment times (0， 30， 60， 90， 105， 120 s) at 700 W microwave output power on the subunit composition， secondary structure and tertiary structure of the protein. Glucono-δ-lactone was also used as inducer to analyze the rheological properties and microstructure of the gel. The results showed that the changes in the subunit composition of the microwave-treated SPI were manifested as a decrease in the β-subunit content of the β-conglycinin as well as the formation of high molecular weight aggregates. When the microwave pretreatment time was 105 s， the content of β-sheet and surface hydrophobicity index S0 in proteins increased by 74.45% and 43.19%， respectively， compared with untreated protein. The particle size distribution of the microwave pretreated protein solution was more uniform than that of the protein heated in a traditional water bath. When the microwave treatment time was greater than 90 s， the solubility reduction decreased to less than 60%， which was lower than that of the protein heated in the traditional water bath (67.5%). Analyzing the rheological properties of GDL-induced proteins during gel formation， it was found that when the microwave pretreatment time was 105 s， the final G' of the protein gel was 2.28 times higher than that of the protein gel heated in a water bath， indicating that the microwave-pretreated protein had better viscoelasticity. Scanning electron microscope revealed that the protein gel treated with microwave for 105 s had more uniform and larger pore structure. These suggest that microwave pretreatment can modulate the protein structure and further affect its functional properties by changing the aggregation state of the protein， which provides a reference for expanding the application of microwave technology in the production process of soy protein isolate and the design and development of new protein products.