The performance of a laser diode (LD) driver is a quite important factor affecting its operating properties, thus it is significant to improve the performance of the LD driver. A novel scheme of designing the LD driver based on field programmable gate array (FPGA) is proposed. Employing FPGA as the controlling center, all the functional modules of the LD driver, including AD/DA converting, temperature PID controlling, invariably current driving, LD protection, input and output circuit, are arranged to operate together harmoniously under FPGA. The LD temperature controlling and current driving circuit based on FPGA is designed and demonstrated, and the performance test is carried out when its operating temperature is among 20℃~30℃. The experimental results show that the operating temperature stability is superior to ±0.03℃, and the driving current stability is ±0.1%.