A cyclotron is a device that uses a combination of magnetic and electric fields to cause charged particles to move in a spiral path, repeatedly accelerating them with a high-frequency electric field. Medium and low energy cyclotrons are applied in the medical field to produce positron-emitting radioactive nuclides. These cyclotrons generate a variety of radioactive nuclides that not only meet the needs of clinical PET/CT scans but also support the use of clinical positron drugs and new drug development in the era of molecular imaging and precision therapy.