In order to improve the operational efficiency of multi-airport terminal area and increase its airspace capacity, a terminal area loop approach route structure and operating rules based on continuous descent operation mode were constructed, and the actual sector structure and data were used for simulation verification in this paper. Firstly, a circular approach route was constructed, which consisted of several elliptical rectangular waiting routes and circular preparation routes. Secondly, the corresponding approach operation rules were designed. Then the aircraft approach sequence optimization model was established, and simulated annealing algorithm was used to solve it. Monte Carlo simulation method was used to calculate the terminal area limit approach capacity. Finally, the actual terminal area (ZSSSAP) structure data was used for example verification. The experimental results show that the instantaneous peak number (21.90%) and the average approach time (3.14%) of aircraft in the terminal area can be effectively reduced by the ring approach route in the busy state, and the average approach time can be further reduced (6.59%) after the sequence optimization. It can increase the terminal area approach aircraft capacity (4.82%). In terms of airspace operation situation, the annular approach pattern can significantly reduce the peak airspace complexity (61.29%).