A one-step method for electrokinetic uranium extraction and separation from sandstone-type uranium deposit is provided, including: using an activating leaching agent to adjust pH of activation environment as pH3, converting uranium elements in sandstone-type uranium deposit into positively charged uranyl and its complexes; applying direct current (DC) electric field with voltage gradient of 0.1 V/cm to 2 V/cm between cathode and anode, and allowing the uranium elements to move toward a cathode chamber under the action of the electric field and to undergo selective reduction by receiving electrons to produce a low-valent insoluble uranium-containing substance precipitated on the cathode surface. The present invention, through activating leaching, allows the formation of positively charged uranium ions and their complexes only, and electrophysical effects such as electromigration and electroosmosis promote directional movement of uranium toward cathode, thereby achieving uranium extraction from a sandstone-type uranium deposit.