Phosphorene, a two-dimensional semiconductor, has promising applications in energy storage, photodetectors, field-effect transistors fields etc., owing to its all kinds of the fascinating properties. However, sluggish electron kinetics and poor stability under ambient conditions restrict the development of phosphorene. Currently, the main method to solve the above challenges is to coat phosphorene with graphene. Nevertheless, the reported method cannot solve the two problems simultaneously and effectively. Therefore, in this paper, a facile and valid method was developed to prepare three-dimensional porous reduced graphene oxide -phosphorene composite by short-time ultrasonic assisting, for the first time. The composite was characterized by XRD, Raman, TGA, SEM, AFM, FT-IR, XPS, UV-Vis and Optical microscope techniques. The relevant results indicated that a strong P-O-C bond between phosphorene and reduced graphene oxide was formed, which makes the phosphorene exhibit excellent stability even when its dispersion in water was exposed to air for 96 h. Furthermore, the three-dimensional porous cross-linked reduced graphene oxide conducive network was also formed, and the pore size of the composite ranges from a few hundred nanometers to several micrometers.