This article provides an overview of the pretreatments that can be applied to lignocellulosic biomass and their different benefits. It focuses and compiles information on the main physical pretreatments applied to lignocellulose biomass. Concept, advantages, disadvantages and parameters of the pretreatments (milling, ultrasound and microwave). As well as a review of research carried out on different types of biomasses and what was obtained from them. Milling provides an essential mechanical change to optimize the surface, while microwave and ultrasonic methods provide sophisticated techniques that greatly increase the efficiency of transforming biomass through selective structural modification.