A FCFMSIL radar includes a SILO, a frequency conversion unit, an antenna unit, a demodulation unit and a processing unit. The frequency conversion unit converts an oscillation signal of the SILO into a FMCW signal. The antenna unit transmits the FMCW signal to an area as a transmitted signal and receives a reflected signal from the area as a received signal. The frequency conversion unit converts the received signal into an injection signal and injects it into the SILO. The demodulation unit demodulates the oscillation signal into an in-phase demodulated signal and a quadrature demodulated signal. The processing unit processes the in-phase and the quadrature demodulated signals to obtain a baseband signal and thus acquire a phase and a frequency of a tone in the frequency-domain baseband signal, and determines the tone corresponding to one or multiple objects based on the phase and frequency of the tone.