The magnet system of China fusion engineering test reactor (CFETR) includes toroidal field, central solenoid (CS) and poloidal field coils. The design and fabrication of CS coil are most significant and challenging for China due to the lack of experience. As the core technique of CS coil, cable-in-conduit-conductor (CICC) has been chosen to ITER CS conductor with the short twist pitch (STP) cable pattern. STP cable pattern has been demonstrated to avoid the performance degradation of conductor after electromagnetic cycling and warm-up-cool-down thermal cycles during operation. For qualifying the manufacturing process and performance of conductor, two short sample conductors were manufactured at ASIPP and tested at Swiss Plasma Center. Performance tests include DC test, Tcs, AC loss and MQE (Minimum Quench Energy) measurements. This paper is mainly about the stability analysis, and the energy margins of the conductor at various operation conditions are investigated with test data and model simulation.