The invention discloses a multi-objective optimization method of a reactive voltage in a wind power plant. In order to solve a problem that the existing wind power plant operation mode can not realize compatibility of stability and economy effectively, the method sets economic and stability objectives for wind power plant operation. A multi-objective optimization control model of a wind power plant reactive voltage is established by using reactive powers of an SVC and a doubly fed wind turbine as control objects. With a fuzzy multi-objective decision-making method, optimization of the reactive voltage of the wind power plant is converted into a multi-objective multi-constraint non-linear planning problem for solution. Therefore, economic and stability objectives of the wind power plant operation can be achieved; and thus voltage stability of the wind power plant can be improved and the wind power plant losses can be reduced reasonably.