In this paper, the silicon-rich SiCx thin films with silicon quantum dots are prepared at different annealing temperatures by magnetron co-sputtering, microwave annealing and rapid thermal annealing. The thin films are characterized by grazing-incidence X-ray diffraction (GIXRD), Raman spectrum, and photoluminescence (PL) spectra technology. Influences of annealing technologies on the number and the size of silicon quantum dots, crystallization rate, and photoluminescence peak are discussed. The results show that compared to the rapid thermal annealing process, microwave annealing can not only lower the formation temperature of silicon quantum dots (200 ℃), but also reduce the β-SiC quantum dots formation temperature (100 ℃). At the same annealing temperature, the number, crystallization rate and photoluminescence peak intensity of the silicon quantum dots prepared by microwave annealing are much higher than that of the rapid thermal annealing. The number of the silicon quantum dots is the most, the silicon quantum dots size is the biggest (5.26 nm), the crystallization rate is the highest (74.25%), and the photoluminescence peak is the strongest when the temperature of microwave annealing reaches 1000 ℃. The results show that high-quality silicon quantum dots can be precipitated by microwave annealing.