A control technique for an injection-locked phase-locked loop (ILPLL) includes the following steps: providing the ILPLL with a sampling clock and an injection clock for an integral path and a proportional path of the ILPLL, respectively; making a change in the power level of the injection clock to get the phase error of the integral path of the ILPLL; and controlling the phase difference between the sampling clock and the injection clock based on the phase error of the integral path of the ILPLL.