Carbon-based materials with great adsorption performance are of importance to meet the needs of industrial gas adsorption. Being massive agricultural wastes of sugarcane bagasse, China could use this waste into wealth. However, the comprehensive utilization of sugarcane bagasse as precursors for biochar that can be used as adsorbent has not been extensively explored. In this study, a series of in-situ sulfuric acid modified biochar were prepared by hydrothermal carbonization process. The prepared biochar (SBAC-7) is combined of two main advantages that are high microporosity (micropore surface area = 1106 m 2 /g) and rich in S-containing functional groups on the surface. In particular, SBAC-7 showed an excellent adsorption capacity of toluene (771.1 mg/g) at 30 o C, which is nearly 3 times as high as the commercial activated carbons. Meanwhile, it showed great stability and cyclic regeneration performance with five toluene adsorption-desorption test cycles. This study provides a high-performance biochar for adsorption-desorption cycle in practical engineering applications, and would contribute to the sustainable “sugarcane production - bagasse utilization” circular economy.