The invention discloses a screw squeezing dewaterer. The screw squeezing dewaterer comprises a rack body, a driving unit, a screw column, a sieve drum and screw blades, the driving unit and the sieve drum are fixed on the rack body, the screw column is arranged in the sieve drum, the screw blade is arranged on the screw column, the screw column is connected with the driving unit, one end of the sieve drum is provided with a material inlet, the other end of the sieve drum is provided with a material outlet, the material inlet end of the sieve drum is lower than the material outlet end of the sieve drum, and a screw distance between screw blades gradually reduces from the material inlet end to the material outlet end. The screw squeezing dewaterer can realize continuous dehydration, so matching apparatuses in front of and behind the screw squeezing dewaterer can also realize continuous treatment, thereby complex operation control can be omitted. The rotating speed of the screw squeezing dewaterer is low, so required running power is small, thereby the daily running cost is low. The screw squeezing dewaterer has the advantages of total utilization of sludge, no residual, no emission, and realization of sludge harmlessness and recycling.