Abstract: the principle of equity is the national tax system to establish the basic starting point and basic principles of fair personal income tax system will be able to fully play its regulating equitable income distribution and unique features, however, due to the tax model, the rate structure, fees deduction and tax collection, etc. defects, leading to our current lack of personal income tax system fair and very serious, therefore, must be comprehensive reform of personal income tax system, through changes in tax model, the scientific design of tax structure, reasonable regulations and improve the standard expense deduction of tax collection, etc. reforms to improve its fairness, in order to effectively perform its regulatory function, to achieve social equity objectives.