In this paper, we employ an express and high-throughput method fabricating micro-and nano-grooves for liquid crystal (LC) molecules alignment. Splitting the polymer film triggers the crack front vibrating back and forth between the two substrates. The propagating wave front brings out self-assembled polymer grooves extending over a large area. The period of the crack induced self-assembled grooves is tunable which consists with the theoretical prediction. This crack-induced grooving (CIG) method can avoid the drawbacks caused by traditional rubbing and provide anchoring energy comparable to that using polyimide rubbing. This novel CIG method offers an appealing alternative to existing technologies for LCs alignment.