Abstract: Amphibious vehicles, which are suitable for a variety of complex land and water terrains, have significant strategic and economic value. Conventional amphibious vehicles typically require two separate drive systems for land and water, which makes their propulsion mechanisms complex and the transition between modes relatively slow. To address this, in this paper, a high-speed amphibious unmanned vehicle using a single drive system with paddle-wheels was developed, and prototype development and testing were completed. The high-speed amphibious prototype vehicle has overall dimensions of 800 mm×540 mm×350 mm, with a weight of 9 kg and a maximum load capacity of 3 kg, a maximum speed on land of 22 m/s, and a maximum speed on water of 12 m/s. At the same time, a numerical calculation method for the integrated control of amphibious vehicles and paddle wheels is established. Through a combination of numerical simulation and experimental studies, the navigation characteristics and hydrodynamic formation mechanisms of paddle wheel-driven amphibious unmanned vehicles were investigated. Research has shown that the vehicle generates dynamic lift through high-speed rotation of four paddle wheels while navigating on water, reducing the submersion depth of the vehicle body, and even allowing the body to lift out of water, achieving higher navigation speeds. During stable navigation, the paddle wheel-driven amphibious vehicle exhibits periodic pitch motion, with the front and rear wheel draft depths fluctuating between 0～0.25D and 0.5D ～0.75D, respectively (D is the diameter of the paddle-wheel). When the vehicle’s pitch angle is at its minimum, both draft depths are large, resulting in increased lift and upward motion. The tail flow from the front wheel increases the draft depth on the rear wheel’s leeward side, causing the rear wheel’s torque reaction to exceed that of the front wheel, which increases the vehicle’s pitch angle. When the pitch angle reaches its maximum, the draft depths decrease, resulting in reduced lift, and the bow of the vehicle begins to descend under the influence of gravity, leading to a gradual decrease in the pitch angle, thus exhibiting periodic oscillations in its attitude. There is a linear matching relationship between the vehicle’s stable cruising speed v_x and the paddle wheel’s linear velocity v_n, which can provide reference for controlling the paddle wheels of amphibious vehicles.