The invention discloses an IC element solder joint defect detection method based on a Gaussian mixture model. The method comprises following steps: initializing template quantities, weights, the mean value and the variance of the Gaussian mixture model, and establishing a frequency distribution graph according to the height and width of a training picture; acquiring an IC solder joint training picture from a training sample, and updating the Gaussian mixture model and the frequency distribution graph; determining whether the training sample finishes training, and calculating a defect degree threshold of the training sample if the training sample finishes training; collecting a picture of an IC element solder joint to be detected, then calculating the defect degree of the picture with the cooperation of the trained Gaussian mixture model and the frequency distribution graph; and comparing the defect degree of the picture and the defect degree threshold of the training sample so as to obtain a detection result of the IC element solder joint. The method is less in calculation amount, rapid in detection speed and high in accuracy, can effectively detect insufficient solder defects of the IC element solder joint, and can be widely applied to the field of IC element solder joint defect detection.