Objective To extract handwritten text messages from the express waybill using Cb color component information of YCbCr color space combining with threshold segmentation method. Methods Firstly, the express images were transformed from RGB color space to YCbCr color space, then image thresholding was performed under image of Cb color component. Finally , median filtering denoising was applied to the extracted handwritten text messages, and the segmentation result was compared with the extraction algorithm based on K-means clustering under YCbCr color space in segmentation effect, splitting time and text recognition rate. Results The results showed that the extraction of the handwritten text using Cb component tended to be clearer and with faster processing speeds and higher recognition rate than in the Lab color space, the average processing time of the express image was 1. 36 s, and the identification rate was 89% . Conclusion Using Cb color component information to extract the handwritten text can get better extraction effect, and the algorithm is simple and feasible.