Estimation for proportion or number of true null hypotheses is an essential task in multiple hypothesis test. One type of estimating methods is based on the graphic of the sorted $p$-values first proposed by Schweder and Spj$\varphi$tvoll(1982). But these methods only utilize the information of a specific cutpoint $p$-value, existing methods may lose efficiency when the deviation between null hypothesis and alternative hypothesis is small. In this paper, we improve estimating methods by taking all information of $p$-values on the null hypotheses. Improved methods are more accurate and efficient than corresponding original methods due to more information can be used. Compared with the existing methods, the accuracy of the proposed methods is competitive through numerical study.