The researchers designed an online live teaching for mathematics gifted students based on some literature related. The teaching media are tablet computer and Tencent classroom application. The content of the teaching is the definition and inference of divisibility in elementary number theory. In order to understand the online learning experience and achievements of gifted students in mathematics, the researchers designed a learning experience questionnaire and learning achievement test questions. The questionnaire contains 9 items, which are designed with reference to previous related studies. Test questions are two related proof questions to test the learning effect of participants. The participants completed the questionnaire and answered the test questions. The researchers analyzed the corresponding data and found that: 1) participants have a positive learning experience for online live teaching using tablet computer; 2) in the test of learning effect designed by the researchers, participants obtained excellent academic results.