The invention provides a method for improving the precision of a right angle cutting experiment of a carbon fiber composite material, belongs to the field of cutting of hardworking materials and relates to the method for improving the precision of the right angle cutting experiment of the carbon fiber composite material. According to the method, a carbon fiber composite material sample is fixed to a rotor of a linear motor, the rotor carries the sample to preprocess the sample through a three-axis grinder, a damaged area below the initial area of the sample is removed, and the surface, to be machined, of the sample has high flatness; an ultra-field-depth microscopic device is used for accurate tool setting, the practical cutting depth is accurately measured and adjusted so that it can be ensured that the practical cutting depth is equal to the preset value of the experiment, and the precision of the right-angle cutting experiment is improved. According to the method, due to building of an experiment device and experiment setting, the grinder is used for preprocessing, and the experiment is completed through the steps of microscopic tool setting, right angle cutting experiment conducting and the like. The device related to the method is simple, easy to operate and capable of effectively improving the experiment precision of the right angle cutting experiment of the carbon fiber composite material.