Abstract: Using the methods of documentary, investigation and mathematical analysis, the paper researches the special characteristics of China’s dominant event of men's 1500m freestyle swimming with the following conclusions:1.The best competitive state of elite men's 1500m freestyle swimmers is between 20-25 years. Sun Yang is still going to be at his prime time for the next Olympic Games. 2,1500m freestyle swimmers’ body shape is characterized by tall, long arms, big hands and feet with significantly "inverted triangle" streamlined body shape and low body fat. 3.Their techniques are characterized by large stroke range,low stroke frequency and obvious rhythms. 4. Their physical fitness features include endurance as the basis, speed as the key and strength as the core.