With microelectronics plane technology, electron beam evaporation is used to deposit metal Au on the surface of n-4H-SiC to form Schottkv contact, alloys Ti, Ni, Ag used to form Ohmic contact on the n＋ backside, the Schottkv barrier ultraviolet photodiode has been fabricated. The spectrum response characteristics and the I-V characteristics of the devices have been measured and analyzed at different temperatures. The measurement results show that the device has lower leakage current at high temperatures. The descendent speed of the forward turn-on voltage is -1.2 mV/℃. The response wavelength range is from 200 nm to 400nm, the peak value of the spectrum response appears in 320 nm at 23 ℃ and 330 nm at 260 ℃ respectively, and the wavelength has red shift about 4 nm every 100 ℃;The sensitivity of response reduces as temperature rises, and it is reduced by 2 times every 100 ℃ on average