Fault signal of rolling bearing is often weak periodic, and the chaotic oscillator is very sensitive to weak periodic signal with specific frequencycan detect the fault signal effectively. he mathematical model and the basic detection principle of the chaotic oscillator were introduced, the determination method of the dynamic critical threshold. The chaotic oscillator detection method was applied to the fault signal of rolling bearing, including the outer ring, the inner ring and the rolling elementwhether there was a fault signal through the changes between the output phase diagrams the detection of the fault signal rolling bearing was implemented effectively.