Improving measuring accuracy of rate biased laser gyro angle rate is important to its application field.The quantization error is found important influence to laser by analyzing random drift of rate biased laser gyro,then a new static angle rate algorithm based on moving average theory is presented,which is also analyzed and simulated.The results shows that with properly grouping parameter selection,the influence of quantization error on rate biased laser gyro angle rate is reduced prominently,and the validity of the algorithm is also proved experimentally.The algorithm can be used in other situation,in which quantization reduction is significant.