The invention discloses a method for rapid determination of the immunoglobulin G (IgG) content in a raw material plasma alcohol precipitation process. Characterized by simple operation and rapid analysis, the method can accurately determine the content of IgG in an alcohol precipitation solution. The specific steps include: (1) collecting samples in the alcohol precipitation processes of different batches of raw material plasma with consistent conditions every 10-15min and conducting centrifugal treatment; (2) employing a near infrared spectrometric analyzer to collect original near infrared spectrums of the samples, and determining the actual IgG content of the samples by a conventional method; (3) correlating the near infrared spectrum data obtained in step (2) with actual IgG content data, using a mathematical method to divide the sample set into a calibration set and a validation set, and utilizing chemometrics software to establish a quantitative model of the calibration set sample IgG content; (4) subjecting all the spectra to first-order derivative +SG9 point smoothing treatment, then establishing a model, and comparing the influences of different variable selection methods on model establishing results; and (5) employing the validation set sample to validate the prediction ability of the established mathematical model.