Intruding metal detection method for induction type power supply system and related supplying-end module

An intruding metal detection method for a supplying-end module of an induction type power supply system having a supplying-end coil includes: obtaining a previous peak trigger voltage measured during a previous measurement period and setting a reference voltage to be equal to the previous peak trigger voltage; interrupting at least one driving signal of the induction type power supply system to stop driving the supplying-end coil during a measurement period, to generate a coil signal of the supplying-end coil; measuring a first peak of the coil signal within an oscillation cycle of the coil signal, to obtain a first peak trigger voltage; comparing the first peak trigger voltage with the reference voltage; and determining that there is no intruding metal existing in a power supply range of the induction type power supply system when the first peak trigger voltage is equal to or close to the reference voltage.