The stable and effective detection and the increased ability of anti-jamming are the main problems to besolved in the laser range finding. In this paper the self2triggering pulsed laser range finding technologywith automatic gain control is proposed. It can not only deduce the measurement tolerance caused by signal rising edge, but also reduce the walk error brought by the variable signal amp litude. The correspondingmeasurement results show that sub-millimeter resolution is obtained over 10m range.