Equal score line is to convert the file scores of college entrance examination over the years through a scientifically designed mathematical model, and change the file scores of candidates with equal scores over the years into the file scores of candidates with the same level in that year, that is, the equal score lines of candidates with the same level over the years are all the same. For example, if a student's score of 20 1 1 liberal arts is 100, and the score of 20 10 liberal arts is 643, then the parity score of the candidate is 20 1 1. That is to say, in previous years, the parity scores of candidates in the same ranking were the same, all of which were converted into 20 1 1 scores of candidates in the same ranking. Isoscore is the core part of the voluntary pilot system, and having complete enrollment data of college entrance examination over the years is the basic guarantee to realize the isoscore principle. The system provides voluntary counseling for college entrance examination candidates by using the method of equivalent analysis and issues a simulated voluntary evaluation report, which can effectively improve the rationality of voluntary reporting and avoid the high risk brought by blind reporting.