There are two methods commonly used to measure bone age, G-P atlas method and integral method, as follows: 1. G-P atlas method: use the bone age atlas book to compare bone age films, this method is easier and saves time, but the repeatability is poor and the accuracy is not enough; 2. Integral method: the bone maturity of 13 small bones are scored by the ossification center separately and then accumulated to get the specific bone age value, this method is more tedious, but the accuracy and repeatability are better, and it is more and more widely used in clinical, sports research departments and judicial departments, and it is important for the identification of minor crimes and the selection of athletes.