Accurate measurement of the timing jitter of femtosecond laser is an important prerequisite to promote its high-precision application. In order to achieve high-precision and no-reference measurement of timing jitter, a measurement system based on fiber delay line was designed and built. Based on the structure of asymmetric Michelson interferometer, a long fiber delay line is added into one arm to identify the time error and improve the measurement accuracy of timing jitter. The timing jitter power spectrum of a lab-made mode-locked fiber laser with a repetition rate of 82 MHz was measured, and the RMS timing jitter was 10.1 fs in the integrated range of 100 Hz to 10 kHz.