An experiment of 355 nm all-solid-state ultraviolet laser direct writing and etching of borosilicate glass is conducted to investigate the effects of laser energy density, repetition frequency, scanning speed, scanning distance and number of scanning on the etching results based on the single variable method. The research results show that, serious collapse phenomena occur in glass if laser energy density is too large. The plasma shielding effect increases and the etching depth decreases with the increase of laser energy density. With the decrease of repetition frequency, the channel edge fragmentation gradually reduces and the etching depth increases. The reduction of scanning distance can effectively improve the channel bottom surface flatness. The etching depth increases with the increase of number of scanning and simultaneously the channel taper increases. Under the optimal processing parameters, the direct writing and etching of L-shaped micro-channel with a width of 84.8 μm, an etching depth of 178 μm, a flat bottom surface and a channel verticality of 89.580° is realized.