A method for the long-term stability improvement of an optoelectronic oscillator was proposed,which is based on a feedback control loop. To achieve the long-term stability,the frequency of optoelectronic oscillator is measured with a field programmable gate array and a frequency dividing circuit. Then the length of optoelectronic oscillator loop is adjusted with a fiber delay line. The accuracy of dividing method to measure the frequency of optoelectronic oscillator is discussed in theory. An experiment based on a single loop structure shows that the phase noise performance does not deteriorate while the long-term stability of optoelectronic oscillator is effectively improved,and the frequency stability of optoelectronic oscillator with feedback control loop is ±0.8 ppm over 7 hours.