The utility model relates to a dynamic tensile fatigue simulation testing system for an insulator and connecting fittings. The system comprises coupling mechanisms, a tension sensor, a static-dynamic load combination load mechanism, and a cooling system; the tension sensor, the static-dynamic load combination load mechanism, and the cooling system are respectively connected with a measurement and control system; and the static-dynamic load combination load mechanism and the coupling mechanisms are respectively connected with a pedestal. According to the system, with the measurement and control system, a static tensile force along the axial direction and a dynamic tensile force with the adjustable frequency are exerted on one end of the insulator, thereby establishing a testing condition for the fatigue characteristic research of the insulator under the effects of a static load and a dynamic tensile vibration load.