Abstract: The present disclosure provides a method and device for predicting a production performance of an oil reservoir. The method includes: determining a single-well numerical simulation data set according to geological parameters, rock and fluid parameters and construction data; performing reservoir numerical simulation based on the single-well numerical simulation data set, and determining a standard data set for oil reservoir production performance prediction; establishing a deep belief network (DBN) model for oil reservoir production performance prediction according to the standard data set; and predicting the production performance of a target well by using the DBN model to obtain a production performance prediction result of the target well. The present disclosure can be used to fast and accurately predict the production performance of an oil well in an unconventional oil reservoir. For a given block, the DBN model can be used indefinitely without the target well being put into production.