To realize the parallel electricity generating of a plurality of sine wave generators without synchronous data wires and achieve the goal of connecting the sine wave generators of different powers in parallel by causing each single generator to distribute load according to nominal power and proportion, the invention discloses a control circuit used for the parallel connection of a plurality of sine wave generators and a multi-machine parallel system. The control circuit includes a rectification circuit, an inversion and power control unit, a direct current (DC) voltage sample circuit, a DC sample circuit, an alternating current (AC) sample circuit, an AC voltage sample circuit and a central processing unit. Among all the single generators, the respective physical quantity is independentlydetected and calculated through the respective control circuit to obtain an adjustment value. Subsequently, the actual output power of each single generator is adjusted in real time, thus achieving the matched output powers among all the single generators of the parallel system and the goal of parallel connection among the plurality of sine wave generators with different powers. In the invention,no synchronous data wire is needed and the application occasions as well as the use range of parallel-connection generators are considerably expanded.