Parallel micro/nano lithography is essential for rapidly fabricating microstructures. This review briefly introduces the principle and advantages of parallel micro/nano lithography and then analyzes and discusses spatial light modulator (SLM)-based parallel micro/nano lithography. In terms of modulation to incident light, the principle and progress of SLM-based parallel micro/nano lithography (which is divided into two types, i.e., multifocus parallel lithography and projection parallel lithography) are reviewed. This review summarizes the current situation, existing problems, and future prospects of these two types of SLM-based parallel micro/nano lithography.