The invention discloses an evaluation device of state information of the machining process of a numerical control milling machine. A machining state data collecting array device, an information storage device, a numerical control system and the like on a machine tool are connected into a semi-closed-loop control circuit through the evaluation device MCU. A machining state data collecting array collects state data of main shaft currents, feed currents, vibration, machining temperatures and the like in the machining process of the numerical control machine tool and can intelligently identify abnormal states of abrasion and breakage of a cutter, material defects of workpiece blank and the like. A communication unit can achieve real-time connection between the machining state information collecting array and the evaluation device MCU. The evaluation device MCU checks and analyzes collected machining state parameters according to a certain algorithm, generates a check report and guides the information storage device to update the optimal parameter record. Meanwhile, the evaluation device has the prejudgment function, submits alarming when meeting with problems which cannot be dealt with and meanwhile analyzes corresponding error reasons and provides proper solutions. According to the evaluation device of the state information of the machining process of the numerical control milling machine, the machining parameters of the milling machine and the state information of the machining process are checked.