This paper mainly aims at BPSK signals to establish and validate a timing estimation method named as WP.Z algorithm that uses two samples/symbol sampling rate and its modified algorithm. Both of them have been carried on modeling and simulating in detail and their performance is evaluated under various parameters. It is not only discussed the accuracy, astringency and applied bound between two algorithms, still simulated and verified each parameter's influence to algorithm, the result is that in a low SNR and short interval length environment, the modified algorithm can be improved significantly compared to the basic algorithm.