Abstract: Reconstructed model technique is successfully applied to measure short fatigue crack length in the testing work. According to elastic-plastic fracture mechanics method, it is put forward an estimated formula for short fatigue crack propagation rate at notch. Using △ε_p (effective plastic strain range of crack tip) as a controlling parameter, the solution to the normalizing problem of propagation rate of short fatigue crack as well as long fatigue crack at notch for 45^# steel are given.