Conventional upconversion nanoparticles (UCNPs) based nanoplatforms have achieved significant progress in many fields during the past decades, and with the development of nanoscience and nanotechnology, more and more complex situations need UCNPs based nanoplatforms due to their ability to load multiple molecules and also activate them independently when necessary. Only the UCNPs with switchable emission can meet this requirement. This review provides a summary of the optimization of synthetic approaches for the recently developed UCNPs with switchable emission and summarizes their various applications in programmed therapy. And also, the challenges and limitations UCNPs face and the potential solutions are discussed.