<p>Underwater Gliders (UGs) have emerged as vital instruments in marine research, offering distinct advantages including low operational costs, extended range capabilities, and superior durability. Traditional UGs, however, face limitations due to their substantial size, weight, cost, and deployment complexity. Moreover, the conventional oil pump method for buoyancy adjustment exhibits slow response times, resulting in increased unsteady gliding depth ratios. These constraints limit their application in shallow water environments such as ports, coastal waters, and inland water bodies. This paper presents the TL-200, a small-sized underwater glider that incorporates an integrated buoyancy-driven and attitude adjustment mechanism. Through the implementation of an innovative buoyancy drive unit, the TL-200 achieves enhanced buoyancy regulation response while maintaining a simplified structure compared to conventional gliders. A dynamic model for the TL-200 was developed and validated through comparative analysis of numerical results and experimental data. Utilizing this dynamic model, motion simulations were conducted to examine the influence of metacentric height on motion parameters. Additionally, the study evaluated the gliding efficiency and energy consumption of the TL-200 under varying buoyancy adjustments. The findings demonstrate the effectiveness of this small-sized underwater glider’s integrated buoyancy-driven and attitude adjustment mechanism.</p>