According to the FDBR standard and the principle of uncertainty,the calculation method of low heat value (LHV) of  municipal solid waste(MSW) incineration power plant was introduced,and the uncertainty calculation model of LHV of MSW was constructed. Taking a 935 t/d MSW incineration boiler as the research object,the LHV of MSW was calculated and analyzed,and the uncertainty of LHV test was evaluated. The results show that the matching degree of the LHV of MSW into the furnace and the designed LHV of the MSW incineration power station directly affects the operation state of the MSW incineration boiler. The tracking and analysis of the LHV of MSW should be strengthened. Compared with the MSW sample test,the performance test method can better reflect the real situation of LHV of MSW into the furnace. According to the FDBR standard,the average value of the LHV of the furnace waste during the performance testing can be accurately obtained,and the test accuracy is high. However,the operator is still unable to adjust the running state of the unit in real time according to the furnace waste. The real-time prediction of the LHV of the furnace waste is still the focus of the current stage. The measurement uncertainty of superheated steam mass flow,municipal solid waste mass flow,flue gas volume flow at economizer outlet,slag loss on ignition,economizer inlet feed water temperature,superheated steam temperature,air temperature in the middle section of primary air preheater,the ratio of wet furnace slag,economizer outlet flue gas temperature accounts for 99.3% of the uncertainty of LHV of waste into the furnace. Improving the measurement accuracy of these nine parameters can ensure the test quality of the LHV of MSW.