A tool management system of machine tools includes a reader, a receiver, a storage unit, a processor and a control unit. The reader is configured for reading at least one category parameter of the tool according to a tool index code of the tool. The receiver is configured for receiving real-time process information of the tool with a preset periodicity. The storage unit is configured for storing the tool index code, the category parameter, and the real-time process information. The processor is configured for processing a weighting algorithm to obtain a result according to the category parameter and the real-time process information. The control unit is configured for sending a control instruction according to the result.