The invention discloses a phase locked loop (abbreviated as PLL) self-calibration circuit. The PLL self-calibration circuit is configured in such a way that a first counter counts an output clock of acrystal oscillator (abbreviated as XTAL); a second counter counts a frequency division clock of a voltage controlled oscillator (VCO for short); a binary search circuit outputs a switch capacitance control word of an inductance and capacitance oscillator corresponding to a preset frequency point; a lookup table circuit outputs a switch capacitance control word difference of a target frequency point relative to a center frequency point; and a fine adjustment control circuit, according to the binary search circuit, the lookup table circuit and analog comparators, outputs a switch capacitance array control word corresponding to the target frequency. According to the invention, the capacitance value of a switch capacitance array in the inductance and capacitance oscillator is controlled through a digital circuit, a frequency tuning curve is expanded from one to multiple, and a PLL can be rapidly locked merely through fine tuning during frequency point switching by saving the switch capacitance array control word of the center frequency point and switch capacitance array control word difference between the target frequency point and the center frequency point.