Abstract: In order to reduce the data delay in the ring laser gyro (RLG) and adopt it in the fast tracking application, the small delay dither signal removal method was proposed based on recursive least-squares(RIS) adaptive filter. Firstly, the theory of RIS adaptive noise cancelling was described. Secondly, the hardware was designed through which the dither feedback signal after A/D transfer and RLG readout signal could be sent to computer via universal serial bus interface.Finally, the RIS adaptive software was programmed to remove the dither signal based on MATLAB.The residual count of deprived signal filtered by an 11-order finite impulse response(FIR) filter is corresponding with that of original ItLG readout signal filtered by a 31-order FIR filter, but the latency is smaller.Experiments show this algorithm has a faster convergence speed and the dither signal can be removed effectively.