As a new research area, laser surface wettability modification brings new applications for both laser and materials for industry. The picoseconds (10 ps) pulse laser surface micro-processing over alumina covered aluminium is researched. In the experiment, 10-ps laser pulse is employed and the energy threshold for different laser wavelength and repetition rate is measured. At the repetition rate of 5 kHz, the energy thresholds are: 1 064 nm: 4.0 \mu J/pulse, 532 nm: 2.8 \mu J/pulse, and 355 nm: 4.2 \mu J/pulse. Picoseconds pulse laser is demonstrated feasible in surface scanning at industrial level.