Abstract: It is very important for satellite interference source to have accurate positioning.However,the key to positioning is parameter estimation.In order to improve the positioning accuracy of interference source,we have to estimate the time difference parameters accurately.The traditional generalized cross correlation method improves the effective components of signal by using weighting function while results in the problem of time difference accuracy.Furthermore,in cases of low signal to noise ratio,its estimation performance falls.A generalized correlation time delay estimation algorithm was proposed in this paper based on the second correlation.The second correlation was used in the algorithm to deal with the received signal and suppress interference noise effectively.Then the result of the second correlation by using generalized cross correlation method to further suppress interference noise and improve the signal to noise ratio.As a result,the time difference estimation accuracy was improved.