Related to a method and system for automatically detecting and analyzing pediatric ECGs, the invention comprises a signal acquisition system, a lead number determination module, a QRS wave positioning module, a P and T wave positioning module, a template and waveform analysis module, an automatic comparison module and a display and print module. The invention is a computer-aided analysis to the electrocardiograms of pediatric patients under the age of 16, applicable to the electrocardiograms of children acquired by different numbers of leads, and can be more widely used in clinical application. Moreover, the invention adopts the combined single-lead and multi-lead method to position the easily interfered characteristic points of P, QRS and T waves of pediatric ECGs. Therefore, this method can avoid the errors caused by single-lead calculation, guarantee the accuracy of parameter calculation, and consequently guarantee the accuracy of final automatic analysis results.