With the development of integrated circuits,the power consumption problem attracted widespread concern.Researchers hope to reduce the circuit power consumption.The method of low-power circuit design gets a wide range of applications.The low-power sampling systems have lots of advantages,such as simple structure,low power consumption,long using life.In order to guarantee low-power sampling system to work properly,we must be able to estimate the power consumption of the system and forecast the life of system.Now,most system-level power estimation methods are modeling and simulation.The modeling process of this method is cumbersome and requires a lot of simulation vectors,and simulation time is long.This method is not suitable for simple-structure low-power sampling systems.We put forward a power estimate consumption method,in which system is highly abstract and then mathematical model of power consumption is established.By the data from accelerated life test,we can fit the parameters of the model,in this way we can estimate the life expectancy of the system in a short time.