Abstract: Mercury method is adopted to measure hydrogen escape curves in deposited metals of three kinds of electrodes at constant temperatures,the relationship between hydrogen escape velocity and residual hydrogen content is deduced.Based on the relationship,mathematical model of diffusible hydrogen escape velocity v_H= k·C_H^α is established.With residual diffusible hydrogen content as its argument,the model can charavcterize the correlation between v_H and C_H preferably.