The influence of difference sampling distances in detonation velocity testing for the detonating cords was studied and the testing method was improved. A thin film Mn-Cu sensor was used to test the output shockwave pressure of the detonating cords. On basis of the testing methods,the key affecting factors detonation velocity and shockwave pressure of detonating cords were researched. The testing conditions include temperature,flexibility,linear and non-linear. The conclusions was theoretically analyzed which was based on the semi-empirical formula and the testing results. On basis of the conclusions,mild explosive circuits can be designed more accurately.