1. A method for predicting machining quality of a machine tool, the method comprising: correlating each of at least one product accuracy item with a plurality of operation paths of the machine tool, thereby obtaining a plurality of relationships between the at least one product accuracy item and the operation paths; operating the machine tool to process a plurality of workpiece samples according the operation paths, and collecting a plurality of sets of sample sensing data of the workpiece samples associated with the operation paths during the operation of the machine tool, wherein the sets of sample sensing data are obtained from at least one sensor installed on the machining tool; measuring each workpiece sample with respect to the at least one product accuracy item, thereby obtaining at least one set of quality sample data of the workpiece samples for the least one product accuracy item; filtering and converting the set of sample sensing data of each workpiece sample into at least one set of sample feature data corresponding to at least one feature type; establishing a predictive model with respect to the at least one product accuracy item using the at least one set of sample feature data of each workpiece sample and the at least one set of quality sample data of the workpiece samples in accordance with a predictive algorithm and the relationships; operating the machine tool to process a workpiece according the operation paths, and collecting a set of sensing data of the workpiece associated with the operation paths during the operation of the machine tool, wherein the set of sensing data is obtained from the at least one sensor installed on the machining tool; filtering and converting the set of sensing data of the workpiece into at least one set of feature data corresponding to the at least one feature type; and inputting the at least one set of feature data of the workpiece into the predictive model to conjecture at least one predicted accuracy value of the workpiece with respect to the at least one product accuracy item.