A distant measurement method and a distant measurement system are provided. The distant measurement method includes the following steps: emitting a first light beam and a second light beam from an emitting terminal, wherein the first light beam travels toward a target; providing a switching sequence by a switch mechanism; placing a receiving terminal to receive the first light beam reflected from the target in accordance with the switching sequence and correspondingly provide a first electrical signal, and to receive the second light beam and correspondingly provide a second electrical signal; and utilizing a controlling terminal to receive the first and second electrical signals, and calculate distance between the distant measurement system and the target in accordance with a phase differential formed between the first and second electrical signals.