Abstract: In order to investigate the friction mechanism and wear law of diamond-like carbon (DLC) film, the DLC film was firstly prepared in the method of melting crystal carbon at high temperature and quenching it at rapid speeds based on molecular dynamics simulations. A hemispherical indenter was then used to perform friction behavior on the DLC surface. The prepared film has the density of 2.72 g·cm^-3, with sp² and sp³ hybridization fraction of 37.1% and 60.4% respectively. The friction results show that the wear rate increases linearly with the load under 120 nN and this is in agreement with Archard's wear law. Whereas, the wear rate decreases with the friction velocity because of the effects of velocity on stress distribution and cutting depth. If Si atoms are embedded into the film as inclusion and the inclusion content increases from 0% to 25%, the wear rate will firstly decline and then rise. Finally a wear model among inclusion content, friction velocity and wear rate is established according to the wear datum under a certain load of 50 nN, with the relative error less than 10% to simulation results. The wear model indicates that the minimum wear rate occurs when the film has the Si content of 7.2% with a constant load and friction velocity. The wear model provides an efficient and convenient method for predicting inclusion content on line.