In order to increase the flexibility of control for serial DAC, a new control method for DAC based on FPGA is proposed in this paper. A state transition diagram can be drawn according to the timing diagram of DAC, Which can be realized in FPGA using Very High-speed Integrated Circuit Hardware Description Language. The simulate results show that logic in FPGA is consistent with the requirements. The module based on FPGA can be modified just by modifying software, not the hardware.