Abstract: The V-type artificial main power network and a signal analyzer are usually employed coordinately to check the power line carrier communication equipment. However, it is inconvenient in field tests and the analyzer is expensive. A handheld spectrum analyzer with STM32F407 CPU was designed to identify the interference of 220 V power line. The filter circuit of carrier wave was made up of a series of RC high-pass filter and one-pole active high-pass filter. The hardware was simulated by combining software of Multisim and TINA-TI, in order to verify its capacity of carrier extraction. The carrier signal was sampled by STM32F407 chip, transformed by fast Fourier transform(FFT)algorithm into the frequency spectrum and displayed on an LCD screen. Experimental results showed that this handheld spectrum analyzer could capture wideband signals from 40 kHz to 500 kHz and analyze frequency spectrum of various power line carrier modules accurately and rapidly. Comparatively, the advantages of the proposed power line carrier spectrum analyzer are portable and cheap.