With the continuous expansion of civil aviation fleets and the broadening of route networks, the aviation industry confronts escalating challenges stemming from increased air traffic flow, heightened density, and limited airspace resources. In order to solve this problem, the International Civil Aviation Organization (ICAO) advocates for the adoption of a forward-looking air traffic control system, underpinned by the 4D Trajectory Based Operation (TBO) paradigm. The precise forecasting of aircraft 4D trajectories is essential, serving as the foundation of TBO. Due to the influence of many uncertainties in flight, the real-time position of aircraft will inevitably be inconsistent with the prediction, and flight Conflict Detection (CD) and Conflict Resolution (CR) have become the key issues that must be faced directly. In order to better cope with the development of TBO, this paper reviews the related researches from the three aspects of aircraft 4D trajectory generation, trajectory Conflict Detection (CD) and Conflict Resolution (CR), and discusses the next research direction.