Solvothermal techniques were developed on the hydrothermal methods, and such methods especially in in situ fields have advantages in constructing functional three dimensional (3D) graphene-based composites in many aspects. To verify this concept, we presented in this article by comparing their application on the preparation of 3D Fe2O3/graphene sheets (Fe2O3/GS) composites, which are used as anode materials for lithium-ion batteries (LIB) and served as a probe here for exploring the merits from in situ solvothermal techniques. The ex situ solvothermal and in situ hydrothermal methods were adopted for comparison purpose. Physically, it was found that the in situ solvothermal process facilitates forming attractive interfacial interaction between GS and Fe2O3 resulting from the well wrapping and homogeneous distribution of nano-Fe2O3 particles into the 3D GS matrix and the forceful Fe–O–C bonds between nano-Fe2O3 and few-layer GS. We also confirmed electrochemically that the as-prepared 3D Fe2O3/graphene prepared by a in situ solvothermal technique showed better performance than those obtained via ex situ solvothermal and in situ hydrothermal methods. The in situ solvothermal strategy, if well engineered, can be extended to the synthesis of other high-performance 3D graphene-based materials for many other applications.