The invention relates to a bilateral negotiation electricity transaction system and method, and belongs to the technical field of the on-line transaction of an electricity market. The system comprises the following structures including a first interface module, an identity authentication server, an electricity information management server, a second interface module, a transaction authentication server, a third interface module, a transaction management server, a fourth interface module, a transaction checking server, a transaction execution server and the like. By use of the system, the transparency, the processizing and the informatization of the bilateral negotiation transaction of the electricity market can be realized, the criterion of annual security checking and monthly security rechecking can be optimized, the problems that a transaction result lacks security, normalization and fairness due to a complex coordination mechanism during artificial transaction in the past are solved, and the system is easy in popularization and application.