Based on the white sequence and grey sequence of an interval grey number sequence of standardization, two new unbiased grey prediction models are built respectively in order to improve the accuracy of the interval grey number prediction model. The method of parameter estimation of the model is studied, and its time response expression and the final restored expression are deduced by using Cramer rule. Finally, the proposed model is applied to forecast the number of urban migrant workers, and compared with the existing method. The results show that the performance of the proposed grey model is superior to the traditional prediction model of interval grey number. The result has a positive significance on enriching and perfecting the system of the interval grey number prediction model methods.