The invention discloses a microwave temperature measurement system based on fluorescence fiber temperature measurement and relates to the field of the microwave and optical fiber sensing technique. The microwave temperature measurement system comprises a measurement device, an external optical fiber, an internal optical fiber, a fluorescent probe and an optical fiber adapter, wherein one end of the external optical fiber is connected with the measurement device; the other end of the external optical fiber is connected with the optical fiber adapter; one end of the internal optical fiber is rotatably connected with the optical fiber adapter; the fluorescent probe is fixed at the other end of the internal optical fiber; the optical fiber adapter is fixed in a bore of a microwave cavity; thefluorescent probe is used for receiving optical signals emitted by the measurement device and transmitting fluorescent signals of fluorescent substances on the fluorescent probe excited by the optical signals; and the measurement device is used for measuring the temperature of substances to be measured according to the fluorescent signals. The system achieves the accurate temperature measurement for the substances to be heated in the microwave cavity in the environments of ultrahigh frequency, strong electromagnetic fields and high interference; the adapter is free from the microwave interference; and the system has little microwave leakage, high stability and is simple in structure and simple and convenient in use.