An approach of fabrication of microlens arrays using spatial light modulator based lithography method is proposed. Combined with themal reflow method, digital micro-mirror device is used to pattern microstructure, and microlens arrays with arbitrary structure and topology can be obtained. The patterns on thick photoresist layer are projected by an infinity-corrected optical system. Good surface quality can be realized by thermal reflow method. Compared with classical stereolithography and mask-based exposure lithography method, the proposed method has the advantage of low-cost and high efficiency, especially suitable for fabricating microlens arrays which feature size ranging from several micrometers to hundreds of micrometers. The obtained microlens array can be transferred to a nickel mold by quasi-lithography electrodeposition and modeling (LIGA) process, which can be used as an imprinting mold. The flexible microlens array film can find wide application in novel ultra-thin liquid crystal displays, organic light-emitting diodes (OLED), etc.