Distance measurement method and system

The invention discloses a distance measurement method and system. The method comprises the following steps: generating a single-tone signal and an orthogonal signal of the single-tone signal; transmitting the single-tone signal to a reflecting surface, and receiving a reflected signal of the single-tone signal; calculating a propagation time delay phase of the reflection signal according to the single-tone signal, the orthogonal signal, the reflection signal and preset sliding integral time; and calculating the propagation time delay of the reflection signal according to the propagation time delay phase of the reflection signal and the generation time of the single-tone signal so as to obtain the distance between the reflection surface and the signal emission position. According to the invention, the preset sliding integral time is set to be the integral multiple of the half cycle of the single-tone signal, so that the calculated propagation time delay phase is irrelevant to the amplitude of the reflected sig