The invention provides a system and a method for detecting the crimping quality of an end fitting of a composite insulator. The system comprises a horizontal lathe and a pull rod arranged in the horizontal lathe, wherein a tensile load device used for providing pull force for a to-be-detected composite insulator and a torsion load device for providing torsional force for the to-be-detected composite insulator are sequentially arranged on the pull rod in a sleeving manner; a sample end of the torsion load device is connected with one end of the to-be-detected composite insulator, and the other end of the to-be-detected composite insulator is connected with a mobile locking device; a testing device used for acquiring the deformation condition generated when a material of the to-be-detected composite insulator is damaged is further arranged at the sample end of the torsion load device; the output end of the testing device is connected with a computer. The system and the method are used for analyzing the crimping condition of the end fitting of the composite insulator by simulating the static tensile load and the dynamic torsional load borne by the composite insulator in the actual on-line operation process and by comprehensively utilizing the detecting device.