The invention discloses a process simulation software based atmospheric and vacuum distillation unit optimization operation system and method. The system comprises a system login module, a parameter setting module, a data acquisition module, a data processing module, a simulation computation module, a sample acquisition module, a model building module, an optimization computation module and a result verification module. The system is based on process simulation software Aspen Plus, a severe device operation model is built to more accurately reflect the rule of operation parameters and operation results, a simplified operation model is built on the basis, a multi-objective optimization algorithm is utilized for optimization computation, check operation is realized under the condition that product quality is assured, optimization results can be calculated quickly when raw material composition and properties are changed or the processing scheme is changed to have the operation parameters adjusted, and the device is enabled to obtain maximum benefit.