This paper constructs a conservative votes allocation model for intra-organizational voting. By applying this model, we can calculate the amount of steady elected votes and the number of elects for our party. As to reach the votes allocation purpose, this paper also proposes a mathematical programming model to minimize the total cost or total difficulty for votes allocation. At another situation, if the majority of voters are non-structure, this paper applies a statistical sampling theory to decide the sample size and thus to control the type Ⅰ error. Base on the sample survey, we can estimate the amount of votes for each candidate. By applying the recursive computing method, we can obtain the least votes for elect, then we can adopt leverage votes allocation method for our structural voters. Finally, we also formulate a mathematical model to minimize the total cost or total difficulty for votes allocation. In this paper we propose three theorems for single voting system and prove its existence.