Abstract-Support Vector Machines (SVM) are popular machine learning algorithms that have been successfully applied in diverse aspects, but for large training data sets the processing time and computational costs are prohibitive. This paper presents a novel fast training method for SVM, which has been applied in the fault diagnosis of a service robot. First, sensor data were sampled under different running conditions of the robot and those samples were divided as training sets and testing sets. Second, the sampled data were preprocessed and a principal component analysis (PCA) model was established for fault feature extraction. Third, the feature vectors were used to train the SVM classifier, which achieved the fault diagnosis of the robot. To speed up the training process of the SVM, on the one hand, sample reduction was done using the proposed support vectors selection (SVS) algorithm, which can ensure good classification accuracy and generalization capability. On the other hand, we took advantage of the excellent parallel computing abilities of a Graphics Processing Unit (GPU) to pre-calculate the kernel matrix, which avoids recalculation during the cross validation process. Experimental results illustrate that the proposed method can significantly reduce the training time without decreasing the classification accuracy.Index Terms-SVM, fast training method, support vectors selection, GPU, robot fault diagnosis.