The invention discloses an automatic sample preparation device for a flow molding clay consolidation sample. The device comprises a ring cutter mechanism (1), a power supply mechanism (2), a vibratingmechanism (3), a scraping mechanism (5) and a conveying mechanism (4). Each ring cutter mechanism (1) is fixed on the vibrating mechanism (3). Each ring cutter mechanism (1) comprises a ring cutter (11), a bidirectional fixing cover (12) and a pressing block (13). Each bidirectional fixing cover (12) comprises an upper screw cap (121), a rubber chassis (122) and a lower screw cap (123). Accordingto the invention, flow molding clay does not flow out from the bottom of each ring cutter; the problem that smoothness of the bottom and surface of a flow molding clay sample is difficult to ensure during conventional sample preparation is solved; through the vibration of a machine, the problem that test data are greatly deviated due to the difference in the strength of manual vibration of operators is solved; and four consolidation samples can be prepared at a time, which greatly improves work efficiency and reduces the difference between different samples.