The fast development of SAW requests higher quality surface of CVD diamond films. Nowadays the mechanical lapping method is one important way to polish CVD diamond films, but the processing cost is high due to the low machining quality and efficiency. This paper reports a new accelerant lapping technology base on mechanical lapping and exploratory studies the role of three kinds of metal of the iron, titanium and nickel in the process of lapping. Firstly, ANSYS/LS_DYNA was used to simulate the process of friction and cutting between the CVD diamond films and abrasive plate of different material to analyze the temperature distributing on the interface and weather it is helpful for lapping. Then, experiment researches were carried out using the abrasive plate with different accelerant materials ratio. The results indicate that titanium is the most potent accelerant for polishing, followed by iron and then nickel. Experimental study also found that the accelerant lapping can carried out effectively by using the abrasive plate made of different metallic materials as accelerant to the diamond film grinding.