The invention discloses a high-density low-parasitic capacitor, comprising a PMOS capacitor, a first capacitor, a second capacitor, a third capacitor and an MIM capacitor, wherein the PMOS capacitor is composed of a polysilicon gate, gate oxide, and a source electrode, a drain electrode and an N-well; the source electrode, the drain electrode and an N-well are connected together; the first capacitor is arranged between the polysilicon gate and the metal at the first layer; the second capacitor is arranged between metals at the same layer; the metal at the first layer is composed of a metal block array, and each metal block and an adjacent metal block thereof are respectively connected with the port A and port B of the second capacitor; the third capacitor is arranged between through holes, and each through hole and an adjacent through hole thereof are respectively connected with the port A and port B of the capacitor; and the MIM capacitor is provided an upper polar plate and a lower polar plate which are respectively connected to the port A and port B of the capacitor. In the invention, the capacitor between the polysilicon gate and the metal layer, the capacitor between the metals at the same layer, the capacitor between the through holes, the MIM capacitor and the like are realized on an MOS capacitor, thus reaching the maximal capacitance on a unit area.