The invention relates to a starch sugar decoloration system and technology. New saccharification liquid enters a decoloration reaction tank for decoloration after being added with new activated carbon through a mixer, and the decolorized saccharification liquid enters a buffer tank and is fed into a first activated carbon filter machine through a conveying pump to be filtered; when the pressure of the first activated carbon filer machine is increased to 0.2 MPa, the new saccharification liquid enters the first activated carbon filer machine at first for predecoloration, is added with new activated carbon, enters the decoloration reaction tank for decoloration again, and then enters a second activated carbon filter machine to be filtered; when the pressure of the first activated carbon filter machine is increased to 0.4 MPa, the machine is stopped, and waste carbon is discharged; the new saccharification liquid enters a second activated carbon filter machine at first for predecoloration, and is added with new activated carbon, decolorized, and filtered through a third activated carbon filter machine; the second activated carbon filter machine is stopped, and waste carbon is discharged; the third activated carbon filter machine is adopted for predecoloration, new activated carbon is added for decoloration again, and the first activated carbon filter machine is used for filtering. Continuous operation can be achieved by adopting only one decoloration reaction tank, the automation degree is high, and the labor intensity of workers is low.