The injection current of the diode laser can be modulated by radio-frequency (RF) signal. The RF signal of 20 MHz is input to the high frequency modulation port of diode laser, and part of it is phase shifted and mixed with the saturated absorption spectral signal then input to the low-pass filter. The resulted similar dispersion signal is used to stabilize the frequency of laser to 6S1/2 (F=4)→6P3/2 (F′=5) transition of cesium atom and the frequency stability is better than 1 MHz in 10 s. The stabilization technology has the characteristics of lower intensity noise and higher frequency capture range.