Abstract: Through static simulation in laboratory under artificial control, sludge degradation model and its effects caused by pH value trend, organism concentration, deposition time and temperature were studied. The resultsshow that pH value decreases at first, then increases and gradually stabilizes;organism concentration has little effect on sludge degradation; the relation between the rate of sludge degradation and its time is r∝t -α ; the effect of temperature on the rate constant of sludge degradation coincides with the Arrhenius exponential expression; the sludge degradation law in laboratory coincides with zero order reaction law.