In order to solve the problem of the difficulties in obtaining consecutive values by the pulse interferometry method, a method of multiple pulse interferometry by using femtosecond optical frequency comb is proposed for the arbitrary and absolute length measurement with high precision. The main principle of the arbitrary and absolute length measurement on the basis of multiple pulse interferometry is expounded, and then the temporal correlation model of multiple pulse train interference fringes is constructed. The peak position shift which can contribute to the distance is analyzed. The effect of dispersion on the correlation fringes is also analyzed. In addition, the effects of the atmosphere environmental variations including temperature, humidity, air pressure, and CO2 content on the air refractive index, which affects the measuring precision, are simulated. The simulation results show that the shift of the peak position of the multi-pulses interference fringes is periodic and monotonous in a period. The change of temperature and humidity is proportional to the change of the peak distance of the multipulse interference fringes，while the change of air pressure and CO2 content is in opposite.