The disclosure discloses a system for optimizing duration time of high-pressure leaching of laterite nickel ore, including a data collecting module, an actual duration time calculating module, an optimal duration time determining module, and a duration time control module. The actual duration time calculating module is configured to obtain an actual duration time of the pulp in the autoclave during the high-pressure leaching process. The optimal duration time determining module is configured to obtain an optimal duration time corresponding to a maximum income value. The beneficial effect of the disclosure is as follows: the actual duration time and the optimal duration time are obtained by inputting an operation condition such as the real-time incoming ore composition, the leaching temperature, and the acid-ore ratio into a calculation model. Thus, the duration time of a high-pressure leaching link of laterite nickel ore can be adjusted according to production fluctuation, and the high-pressure leaching process is always performed in a dynamic optimal state of the optimal duration time. Compared with the typical method for optimizing the duration time by the small test, the method has advantages of fast response and optimized precision.