This paper investigates the fusion analysis of complex multi-directional traffic flows in urban areas based on macroscopic fundamental diagrams with the objective of serving urban traffic management subsystems in Intelligent Transportation Systems (ITS) at rush hour or under special circumstances. Therefore, travel efficiency and regional vehicle accumulation are used as basic parameters to model the macroscopic fundamental diagram based on city-regional road network and traffic flow data. According to the directional influx traffic flow, the city area division is defined, thus a multi-directional traffic flow fusion analysis model can be established. The multi-directional traffic flow fusion analysis model is used to accurately describe the changing characteristics of multi-directional traffic flow and the complex integration between them under the influence of directional incoming traffic in urban road network areas. The analytical model also reveals that in addition to the imposition of boundary control management to limit the influx of traffic, the internal flow in the peripheral area also has a non-negligible impact on the overall traffic system operation.