In order to detect the sizing percentage accurately online, a novel hybrid intelligence method is proposed in this study to build the sizing percentage detection model. Firstly, BP (Back propagation) neural network intelligence method is selected to solve the current difficulties of sizing percentage detection online. And then, the hybrid intelligence method is presented to enhance the accuracy of detection model. Experiments demonstrate that the new sizing percentage detection model based on hybrid intelligence method has good performance. And the results of detection are satisfied to the real production process.