The invention relates to a water drill blank compressing device which comprises a compressing machine. The compressing machine comprises a first hollow rotating shaft, a second hollow rotating shaft,a first roller, a second roller, a gear motor, an air conditioner, an air flue pipe and a discharging mechanism; the first hollow rotating shaft and the second hollow rotating shaft are arranged in parallel, the first roller and the second roller are fixed to the first hollow rotating shaft and the second hollow rotating shaft respectively, and the discharging mechanism is arranged below the firstroller and the second roller; an air outlet of the air conditioner is communicated with the air flue pipe, the air flue pipe is communicated with a plurality of first air jet holes and a plurality ofsecond air jet holes formed in the discharging mechanism, and a discharging outlet of the discharging mechanism is located above a transmission mechanism; the transmission mechanism comprises a box,and a plurality of cooling fans are evenly arranged on the two sides of the box. A blank can be conveniently disengaged from the surfaces of the rollers, the compressing efficiency and quality are improved, and materials can be automatically obtained.