In order to solve the problems of digital control and wide-range input of communication secondary power supply, and realize high power density DC-DC conversion, an implementation scheme of two-stage conversion topology with ADP1046A as the core controller is proposed. The voltage regulation and isolation are implemented in different stages, that is, to achieve the adjustment of the input to the target voltage through the Buck circuit, and the isolation between the input and output through the full bridge circuit. This solution uses the standard I²C interface of ADP1046A to realize the communication between the power control and the host computer. The twostage conversion can not only solve the problem of large transformer size and difficulty in optimization in singlestage conversion, but also greatly reduce the size of the output filter. Using the built experimental prototype to verify the related functions and performance, the experimental results show that the proposed DCDC converter scheme meets the needs of the corresponding products and has practical guiding significance for engineering design.