Electro-excited three-phase brushless hidden pole synchronous generator can change the air-gap magnetic field strength by changing the magnitude of excitation winding current, thus realizing wide-range voltage regulation. Rotor winding is an important part of three-phase brushless hidden pole synchronous generator, which generally uses concentric winding. After the rotor winding with a parallel branch number of one is connected between pole and pole and between coil and coil in same pole, the positive end and negative end of the lead line are fixed on the end face of the iron core and directly led out. The rotor winding with a parallel branch number more than one not only needs to be connected between pole and pole and between coil and coil in same pole, but also needs to select the appropriate parallel connection methods. Different connection methods directly affect the complexity and reliability of the rotor winding. Taking a 10 pole and 5 MW three-phase brushless hidden pole synchronous generator as an example, the different connection methods of rotor winding with two parallel branches are compared. Combining the manufacturability and operability, the optimal connection method of rotor winding is selected, and the generator rotor winding and prototype are manufactured. The results show that this connection method is simple and reliable, which can improve the product manufacturability and effectively avoid the insulation faults of rotor winding.