This study designs a multi-source MRI digital radio frequency transmission method by applying multi-channel parallel transmission technology and digital modulation technology to magnetic resonance imaging (MRI) radio frequency signal transmission. This radio frequency method realizes direct digital frequency synthesis (DDS) through FPGA, stores the radio frequency pulse waveform in the internal memory of FPGA, and performs digital up-conversion (DUC) by means of quadrature mixing. This method is simple and easy to operate, improves the integration and flexibility, and applies multi-rate signal processing technology to improve the flexibility of data rate changes. In addition, it uses the Xilinx’s digital signal processing (DSP) development tool System Generator for design and development, reducing the difficulty of digital development. The design verifies the function of multi-source digital radio frequency transmission, and the simulation and test results prove the effectiveness of the transmission method.