尝试对敦化地震台YRY-4型钻孔应变仪记录的应变地震波持续时间进行研究，以中国台网统一地震目录Ms≥7震级为参考震级，用最小二乘法求得参考震级公式：M_F-P =1.92+1.48lg(F-P)。通过验证，认为该公式有一定意义，为现阶段应变地震波的应用找到一条路径。  

 This paper attempts to investigate the duration of the strain seismic waves that recorded by Model YRY-4 drill strain gauge of Dunhua station, take China Seismic Network Catalog Ms ≥ 7 as reference magnitude, using continued time calculating of Dunhua station strain the magnitude of seismic waves obtained the reference magnitude formula with least squares method: M_F-P = 1.92 +1.48 lg (F-P). By analyzing the validation, the formula we get is meaningful, find a path for the application of strain seismic waves in this stage.