The femtosecond enhancement resonator has important applications in the fields of nonlinear optics, precision spectroscopy, etc. In particular, it has been become a powerful tool of generating ultraviolet optical frequency comb at a high repetition rate in recent years. In this paper, we analyze the characteristics of enhancement and dispersion in the femtosecond enhancement resonator by use of the circulating stable electric field method. The relations between enhancement multiple and fineness and between, resonance bandwidth and fineness as well as intracavity dispersion are obtained. Finally, we experimentally realize the resonance enhancement of 15 fs laser from a Ti:sapphire oscillator at a repetition rate of 175 MHz. The enhanced magnification is about 10.