The influence of electromagnetically induced transparency (EIT) on the cavity ringdown spectroscopy (CRDS) is analyzed theoretically. Utilizing the optical pumping effect of EIT in a three-level V-type structure which can increase the transmittance of the EIT medium, we propose a program to improve the CRDS performance. In the experiment, a V-type EIT is constructed with the D2 line of 87Rb, and the ring-down time and sensitivity of the CRDS system are improved under appropriate light intensity. Finally, the ringdown sensitivity is enhanced to 1.45 times of the original value.