Large-range and high-accuracy absolute distance measurement plays an important role in many practical applications, such as industrial production, aerospace and scientific research, etc. In this paper, a method is proposed for absolute distance measurement by chirped pulse interferometry based on the femtosecond optical frequency comb. The interference spectra obtained in experiments are analyzed by means of the principle of the dispersive interference, and the distance can be determined by the shift of the widest fringe in the interference spectra. An absolute distance measurement system can be set up based on the modified Michelson interferometer with a pair of gratings to chirp the reference pulses in the reference arm. Experimental results are in agreement well within 33 m in a range up to 65 m, i.e. a relative precision of 5.110-7. In addition, the optimization of the measurement uncertainty is theoretically and experimentally performed.