By the study of experience formula and simulated experiment,the shock wave overpressure conversion relation between air blast and underwater explosion was studied.The results show that the shock wave overpressure of air blast and underwater explosion has a quantitative relation when scaled distances r=R/W1/3 were varied within 1.5-2.5,and the conversion formula describing the relation was fit out.By theoretical analysis and empirical data analysis,the conversion method of TNT equivalent of shock wave overpressure of other charges was obtained,the conversion of TNT equivalent of shock wave parameters should be based on the shock wave energy of explosive underwater explosions.By contrast,it was certified that calculated results by experience formularevised with TNT equivalent of shock wave parameters meet the needs of precision engineering design.