In this study, a high-precision pulse laser ranging method, employing sinusoidal amplitude time conversion, is proposed. The method uses a sinusoidal signal as a time reference, and frequency doubling and the clock phase separation technique to control the echo pulse timing by adjusting the pulse emission delay. The signal falls within the 0-./4 interval of the reference sine wave, and then effects piecewise linear interpolation for the given interval to convert the variation of the sinusoidal amplitude into the time required for achieving high-precision ranging. The underlying principle of the method is simple and easy to implement. The experimental results show that when the average power of laser emission is 1 mW, the range accuracy is ± (5 mm + 3 ppm) within 300 m without a cooperation target.