The invention relates to a modelling method for combustion optimization of waste plastics oil refining. A bottleneck problem exists in the conventional combustion optimization of the waste plastics oil refining. The modelling method for the combustion optimization of the waste plastics oil refining is determined by the processes of data acquisition and modelling of the waste plastics oil refining, selection and pre-treatment of a data sample, and establishment of a combustion optimization model of the waste plastics oil refining. The method comprises the following steps of: firstly, acquiringthe combustion situation data of the waste plastics oil refining; secondly, carrying out selection and proper pre-treatment on modelling data to guarantee the predicative capacity and generalization capacity of the model; and finally, establishing the combustion optimization model of the waste plastics oil refining by using a corresponding modelling algorithm and a corresponding optimization algorithm. By the method, a waste plastics oil refining combustion optimization model which is relatively accurate and has relatively high generalization capacity can be established. By the method, the prediction accuracy and the generalization capacity of the model are guaranteed by the data selection and the pre-treatment.