The traditional pulsed laser ranging with direct counting time measurement has low precision. In order to improve time resolution and precision of pulsed laser ranging, the interpolation method of Time-to-amplitude Conversion (TAC) is introduced. Several key points of TAC circuit design are provided here. On the pulsed laser ranging experiment platform, the performances of the designed TAC circuits are tested. The experiment results show that TAC interpolation method improves time resolution of pulsed laser ranging from 10 ns to 20 ps and ranging precision from 1.5 m to 5 cm. At last, the error factors influencing the precision of pulsed laser ranging are analyzed.