The pump sends the sand and water mixture to hydrocyclone, the fine sand with eccentricity is sent to vibrating screen. The fine sand and water are effectively separated after dehydration, and little fine sand and mud go back to washing trough. When the liquid surface of the washing trough is high, the fine sand discharges from output opening. The linear vibrating screen can recover material with concentration 70%-85%. Adjusting fineness modulus can be realized by changing pump rotation speed, changing pulp consistency, adjusting overflow water and changing sand sinking mouth. By the process above, the fine sand recovery system can finish three functions, cleaning, dehydration and grading.