The invention discloses a clock generator based on a phase-locked loop, which comprises a crystal oscillator, a phase-locked loop circuit, a clock adjusting module and a doubling circuit output module, wherein the clock adjusting module is used for receiving a first multi-path clock signal output by the phase-locked loop circuit, respectively adjusts the frequency and the phase of each first multi-path clock signal according to the preset frequency and phase of a target clock signal, and outputs multiple second multi-path clock signals respectively corresponding to all of the first multi-pathclock signals; the doubling circuit output module is used for receiving and merging the second multi-path clock signals output by the clock adjusting module, and outputs the target clock signal with the preset frequency and phase. The invention also discloses a corresponding clock generating method. The clock generator based on a phase-locked loop and the clock generating method can conveniently and flexibly adjust the frequency and the phase of the output target clock signal, and greatly broaden the band width which can be realized.