The invention discloses a broadband power line communication cross-layer resource allocation method with prior hybrid service emergency degree in the technical field of low-voltage broadband power line communication. The method includes the steps that when emergency degree of a user and a fair effectiveness value of the user are determined under hybrid service; according to the emergency degree of the user under the hybrid service, the dispatching priority of the user is partitioned, and then according to the dispatching priority of the user and the fair effectiveness value of the user, the dispatching sequence of the user is determined; the QoS expected rate of the user is calculated on an MAC layer; according to the total number of groups capable of being borne by subcarrier of a physical layer and the QoS expected rate of the user, the user grouping number sent by the physical layer is determined; resource allocation is performed by the physical layer according to the user grouping number determined by the MAC layer. According to the method, through the inter-layer interaction information, the dispatching priority of the user is judged, the dispatching rate is adjusted, and the fairness performance of the user can be improved under the condition that the throughput performance of the system is guaranteed.