According to the engineering practice, the problem of 1 bytes error of the frequency meter and lower amplitude of the signal are found. This paper presents a method of making a frequency meter with the minimum system of C8051F020 and FPGA based on the theory of multiperiods synchronization measurement, and realizes the measurement of frequency and pulse width of the measured signal. The system mainly consists of the signal shaping module, the frequency calculation module, the LCD module. After amplification and rectification, the signal to be measured and the standard signal are input into FPGA. Two signals are counted in FPGA, and MCU calculates and processes the receiving data. Finally, the result of measurement is shown in the LCD. The test show that the system can measure the frequency up to 0.1 Hz~10 MHz, effectively eliminate the error of 1 byte and certain anti interference ability.