The invention relates to a diaphragm type pressure and temperature sensor for fiber optical intelligent well, pertaining to the technology field of intelligent well. The invention comprises a broadband light source, a modularization spectrometer, a data transmission line, a data processor, a first section of optical fiber, a second section of optical fiber, an optical fiber coupler, optical cable, one or more diaphragm type optical fiber temperature and pressure two-parameter sensor probe(s). The broadband light source is connected with the input end of the optical fiber coupler through the second section of optical fiber; one output end of the optical fiber coupler is connected with the optical cable and the other output end with the input end of the modularization spectrometer through the first section of optical fiber and the modularization spectrometer is connected with the data processor through the data transmission line; the diaphragm type optical fiber temperature and pressuretwo-parameter sensor probe is at the other end of the optical cable. The invention has the advantages of good stability under high temperature and pressure, corrosion resistance, long service life, accurate measure, no spark and safe application, etc. being suitable for application at much narrower space under a well to meet the demand for monitoring conditions under the well.