In the research of chaotic masking secure communication, there is a new optimization scheme which can process the Lorenz chaotic masking signal so that it can be similar to the noise in both time and frequency domain. In the processing, different optimization parameters make different effects on synchronous time and synchronous error which are what we focus on. This paper mainly processes and analyses the optimization signals with different optimization parameters. Through a lot of experiments we compare the synchronous errors with different optimization parameters, use data fitting method to get the calculating formula for the synchronous error and find the best selection of optimization parameter in this new optimization scheme which can provide the measured parameter for different errors application requirements in Lorenz chaotic masking secure communication.