Biochars have achieved extensive attention due to their unique pore structure and excellent adsorption performance. However, it is still a great challenge that how to effectively improve their adsorption efficiency and rapidly separate from aqueous phase. In this paper, synthesis methods of magnetic lignocellulose biochar composites are summarized base on the synthesis of magnetic nanoparticles. And the effects of pore forming methods, impregnation ratio, carbonization temperature, carbonization time and carbonization mode on the pore structure are compared. Furthermore, application research, adsorption mechanism and reutilization status of magnetic lignocellulose biochars in water treatment are introduced. Finally, future research emphases and directions for magnetic lignocellulose biochars are proposed according to its current challenges.