A symbol rate testing method based on signal waveform analysis is provided. A signal with a plurality of quasi bits 1 and a plurality of quasi bits 0 is received and sampled within an acquiring time. Maximum values of the quasi bits 1 are obtained by calculating sampling values of the signal at various sampling points. A minimum value among the maximum values is determined as a critical value. Whether a quasi bit 1 is a bit 1 or not is determined according to the critical value, and a total number of the bits 1 within the acquiring time is counted. Similarly, a number of the bits 0 within the acquiring time are also obtained. Thus, the symbol rate is obtained according to the above information.