The invention discloses an integrated system for pre-heating air and condensed water of a turbine in a grading manner by using boiler smoke, belonging to the energy-saving equipment using waste heat. According to the integrated system, smoke with a temperature about 300-400 DEG C at the tail of the boiler respectively enters a normal rotary type air heater, two smoke condensed water heaters and a prepositioned low-temperature air pre-heater, and is discharged from the system until the smoke is cooled to a temperature about 60-100 DEG C, so that the smoke with different temperature grades can be reasonably utilized. Meanwhile, the invention provides a set of a flexible low-pressure heat-backing and heating system of the condensed water of the turbine through a smart design of a pipeline and a valve, so that condensed water in a smoke condensed water heater can be flexibly extracted from a plurality of positions, and the smoke waste heat in various working conditions can be applied well. Furthermore, an air side and a condensed water side can be at an optimal waste heat recovery state when the entire smoke waste heat utilization system at the tail of the power station boiler is in various working conditions.