Abstract: A tandem charge structure of torpedo warhead is designed. The dynamic response of clamped square steel plates under underwater exploding loading of tandem charges is analyzed based on the elastic-plastic dynamic theory. Several underwater exploding tests of the tandem charges with different front-rear weight ratios have been carried out. The results showed that the centre displacement of clamped square steel plate of the tandem charges is much larger than those of single charge in the condition of the same total charge mass, The maximum centre displacement is up to over 36%. The test results showed good agreement with theoretical ones.