The invention relates to a power line communication resource allocation method based on business time delay fairness. The power line communication resource allocation method based on the business time delay fairness is a joint allocation process of multiple time slots, and includes: in resource scheduling of each time slot, summarizing a data acceptance volume of each business in the past time slot, estimating a target data volume needed by the current time slot to transmit by calculating a residual data volume of each business in the current time slot and a residual time slot number of each business in the future time slot, and performing subcarrier allocation of each business according to the estimated target data volume and a channel sate of each business in the current time slot. The power line communication resource allocation method based on the business time delay fairness can use system resources to the utmost, and improves system transmission efficiency. Simultaneously, the power line communication resource allocation method based on the business time delay fairness can consider two factors of the data volumes and the time delay fairness among businesses, and guarantees the time delay fairness among the businesses under the condition that the data volumes of all the businesses are different. Additionally, the power line communication resource allocation method based on the business time delay fairness improves handling capacity of a system through power water filling among subcarriers on the premise of considering the time delay fairness among the businesses.