A 532 nm Nd:YAG 10 ps laser with output power of 3.7 W under frequency of 100 kHz was used for ablating quartz glass substrated Al film with thickness of micron dimension. The relationship between ablation rate and single pulse laser fluence was studied, the high fluence ablation and low fluence ablation regimes for picosecond laser ablating Al film were defined. The effect of spot overlapping rates on profilograms of grooves was analyzed, results showed that the ablation depth changed greatly with spot overlapping rate, and it was difficult to obtain ablation rate theoretically from this experiment. In order to improve the precision of ablated grooves and validate the accuracy of obtained ablation rate from Gaussian Linear method(GL), a muti-pass ablating method was put forward. The ablation rates calculated from GL were compared with Corrected Gaussian Linear method(CGL), experimental results showed that CGL was suitable for calculating ablation rates of grooves. The 3D profilogram of grooves in Al film ablated by 10 ps at different spot overlapping rates were simulated through CGL calculated ablation rates.