Turbine deficiency is the key factor influencing the heat rate of the existing power generation units in China. Analysis was made on the factors influencing the turbine steam path efficiency, and the concept of the turbine steam path audit was introduced. Using the turbine steam path technology, quantitative analysis and calculation for the factors influencing the steam turbine efficiency can be made using relevant tool software, which can help the decision making of the key maintenance area during the turbine overhaul. An example was given for one super-critical steam turbine, including the measurement data got during the turbine overhaul and...