The embodiment of the invention provides a method and a device for fixing price according to the quality for electric energy, and belongs to the field of data processing. The method comprises the following steps that: taking j as 1 to J and i as 1 to I in sequence; obtaining the minimum electricity purchasing cost of the user j on an electricity supply company i and an electric energy quality level of the corresponding user j requirement during the minimum electricity purchasing cost; obtaining the electricity selling earnings of the electricity supply company i; and on the basis of the electric energy quality level of the user j requirement and the electricity selling earnings of the electricity supply company, adopting a particle swarm optimization algorithm to obtain the electricity purchasing quoted price of the electricity supply company i for the electric energy quality level of the user j requirement. By use of the method, through a principal and subordinate method, the electricity supply company can realize contract electricity selling earning maximization, the operation of an own enterprise is reduced, the own electricity purchasing cost of the user can be reduced, and stable electricity energy supply is obtained.