In this paper a research about adjustable narrow-width pulsed laser diode driver was introduced which is based on the Lateral Double-diffused MOS(LDMOS). Through the analysis of the semiconductor laser driving circuit theory, circuit-level model of RF power transistor was established by using PSPICE simulation software to gain more optimized drive circuit with theoretical calculations. High-speed current-feedback operational amplifier effectively improved the slew rate and the narrow pulse signal frequency response characteristic. The experimental results show that the laser diode driver can generate 2 A current and the pulse width is adjustable from 20 ns to CW, the rise time and fall time are below 10 ns, the pulse repetition frequency is adjustable from 0 to 10 MHz, which demonstrates the feasibility of the design idea to further improve the output performance of semiconductor laser.