The invention relates to a system for high-precision measuring of a resistor and a capacitor. The system comprises an input square wave signal generating unit, a level conversion circuit unit, a secondary charging circuit unit, a secondary discharging circuit unit, a logic processing unit, a comparison circuit unit, and a pulse width signal timing unit. The system has the advantages that the RC (resistor and capacitor) charging and discharging time is measured, the purpose of measuring the resistors and the capacitors is realized, and the secondary charging circuit, the secondary discharging unit and the logic processing are additionally arranged on the basis of the RC charging circuit and the RC discharging circuit, so the ascending and descending speed of the output signal is improved, and the single measuring speed is improved; the clock frequency of pulse counting is high, the ns-level measurement of time resolution is realized, the clock frequency is doubled to 200M by an FPGA (field programmable gate array), and the time resolution is 5ns; when the resistor is measured, the larger capacitor is selected to improve the ratio coefficient of pulse counting value to the resistor R is improved, or when the capacitor is measured, the larger resistor is selected to improve the ratio coefficient of pulse counting value to the capacitor C, so the measuring precision and the resolution are improved.