The invention discloses a numerical control machine tool for thread milling and a thread milling processing method. The numerical control machine tool is additionally provided with a thread milling module, the thread milling module comprises a thread-milling processing position analysis unit, a thread-milling turning direction analysis unit, a thread taper analysis unit, a thread helix quantity analysis unit, a thread-milling processing mode analysis unit, a logical judgment unit, a computing unit, an output unit and a feedback receiving unit. The processing method includes the steps that whether the processing position of thread milling is outer circle thread milling or inner hole thread milling is analyzed; whether the thread turning direction is right turning thread milling or left turning thread milling is analyzed; whether a thread is a cylindrical thread or a conical thread is analyzed; whether the quantity of a thread helix is a single or multiple is analyzed; whether the processing mode is rough-processing-containing milling, single finish machining milling or sleeking milling is analyzed; data is output to the numerical control machine tool, and processing is carried out till the shape and the depth which are defined by a user are achieved. According to the numerical control machine tool for thread milling and the thread milling processing method, the efficiency of thread milling processing is improved, the quality and the processing flexibility of a product are improved, and the application range is wide.