为了提高利用压电元件稳频的双频激光器的拍频稳定度，分析了各种误差因素尤其是模牵引效应的影响。考虑模牵引效应后，拍频稳定度的理论值主要由程长、增益和温度的稳定度决定。在恒温室内，同一激光器使用普通电源时拍频稳定度为4.5×10-8，使用高稳定度电源时为1.2×10-9。测量了拍频与电流和温度的关系，证明增益和温度对拍频稳定度有较大影响。因此对采用压电元件稳频的双频激光器，除了稳频精度要高，还必须采用高稳定度电源并消除温度的影响，才能达到较高的拍频稳定度。

In order to improve beat frequency stability in the dual-frequency laser with piezoelectric transducer for frequency stability, various error factors were analyzed, and with special attention on mode pulling effect. Due to mode pulling effect, beat frequency stability was influenced by path length, gain and temperature. When an ordinary power supply was used, the beat frequency stability of the laser was 4.5×10-8 in a constant temperature room. When a high-stability power supply was used, the beat frequency stability was 1.2×10-9. Beat frequency has relation between current and temperature was obtained, which also showed gain and temperature had important influence on beat frequency. Therefore, in order to obtain high beat-frequency stability in the dual-frequency lasers, variations of path length, current and temperature should be reduced.