People getting some fatal disease always ask ”How long can I survive?”during the treatment. Therefore, the analysis of surviving is definitely an important research related to a serious issue of how long to survive with different treatment. And for this research paper , its researching information is collected from the status data, and we intend to calculate its risk function. However, in the paper writen by Yang Ya-Wen in 2009,its topic mainly researches the accumulation of risk function. And the difference between Yang’s paper and mine is the dissimilarity of the restricted conditions. So based on this situation, this study could do better algorithm. Besides, our calculation is more precise than Step function’s Maximun Likelihood Estimator in the simulation research. And more samples this study has, more closer to truth the caculaiton is.