Abstract: To thoroughly investigate the performance improvement laws of high-purity spectrum coupled opto-electronic oscillator (COEO) under ideal conditions and promote the optimization strategy for limiting parameters under practical experimental conditions, this paper conducts a comprehensive analysis of the characteristic parameters of COEO, including phase noise, frequency stability, and mode matching factor, through theoretical simulation combined with actual influencing factors. The study focuses on analyzing the influence laws of energy storage delay fiber length, temperature, and their combined effects on the above three characteristic parameters of COEO. The simulation results show that when the fiber length is 300 m and the temperature is 25 ℃, the phase noise can reach -125.79 dBc/Hz@1 kHz and -145.79 dBc/Hz@10 kHz, the frequency stability can reach 3.3×10^-14@1s, and the mode matching factor is 0.999, demonstrating excellent performance parameters. This provides important reference and support for performance optimization of COEO in practical experimental processes.