Abstract: To solve the problem of the landfill settlement calculation,a model for MSW(municipal solid wastes) compression at constant stress was made.According to the model,the MSW compression was divided into the primary compression and the biodegradation compression.The primary compression is caused by upload.The biodegradation compression is influenced by both the stress and the biodegradation condition.The biodegradation condition includes the organic content and the biodegrading rates.A calculation method for landfill settlement was given,which takes into account both the influences of the biodegradation degree and the multi-loading process.The method of determining the calculation parameters is also examined.