A time-of-flight distance measuring system, comprising: a delay unit, receiving a plurality of delay signals (ds 1 ~ds n) and configured to generate a plurality of delayed pulses (dp 1 ~dp n) according to the plurality of delay signals(ds 1 ~ds n), wherein the plurality of delay signals (ds 1 ~ds n) correspond to a plurality of delay times(t d,1 ~t d,n); a light-emitting unit, coupled to the delay unit and configured to generate a plurality of delayed pulsed lights (LD 1 ~LD n) according to the plurality of delayed pulses(dp 1 ∼dp n); a photosensitive pixel circuit, configured to receive a plurality of delayed reflected lights (R 1 ~R n) corresponding to the plurality of delayed pulsed lights (LD 1 ~LD n) to generate a plurality of pixel signals (p 1 ~p n) corresponding to the plurality of delay times(t d,1 ~t d,n), wherein the plurality of delayed reflected lights (R 1 ~R n) are reflected from a reflector, wherein there is a fixed distance between the reflector and the time-of-flight distance measuring system; a storage unit, configured to store a correspondence between the plurality of delay times (t d,1 ∼t d,n) and the plurality of pixel signals(p 1 ~p n), wherein the correspondence includes a plurality of ratios of the plurality of delay times (t d,1 ∼ t d,n) to the plurality of pixel signals (p 1 ~p n) respectively; and a control unit, coupled to the delay unit and configured to generate the plurality of delay signals(ds 1 ~ds n); wherein the time-of-flight distance measuring system (10 performs a time-of-flight distance measuring according to the correspondence between the plurality of delay times (t d,1 ~t d,n) and the plurality of pixel signals (p 1 -p n). a delay unit, receiving a plurality of delay signals (ds 1 ~ds n) and configured to generate a plurality of delayed pulses (dp 1 ~dp n) according to the plurality of delay signals(ds 1 ~ds n), wherein the plurality of delay signals (ds 1 ~ds n) correspond to a plurality of delay times(t d,1 ~t d,n); a light-emitting unit, coupled to the delay unit and configured to generate a plurality of delayed pulsed lights (LD 1 ~LD n) according to the plurality of delayed pulses(dp 1 ∼dp n); a photosensitive pixel circuit, configured to receive a plurality of delayed reflected lights (R 1 ~R n) corresponding to the plurality of delayed pulsed lights (LD 1 ~LD n) to generate a plurality of pixel signals (p 1 ~p n) corresponding to the plurality of delay times(t d,1 ~t d,n), wherein the plurality of delayed reflected lights (R 1 ~R n) are reflected from a reflector, wherein there is a fixed distance between the reflector and the time-of-flight distance measuring system; a storage unit, configured to store a correspondence between the plurality of delay times (t d,1 ∼t d,n) and the plurality of pixel signals(p 1 ~p n), wherein the correspondence includes a plurality of ratios of the plurality of delay times (t d,1 ∼ t d,n) to the plurality of pixel signals (p 1 ~p n) respectively; and a control unit, coupled to the delay unit and configured to generate the plurality of delay signals(ds 1 ~ds n); wherein the time-of-flight distance measuring system (10 performs a time-of-flight distance measuring according to the correspondence between the plurality of delay times (t d,1 ~t d,n) and the plurality of pixel signals (p 1 -p n).