Dense apodized fiber Bragg grating arrays were on-line fabricated on a fiber drawing tower and used for temperature detection of small-scale heat sources. The signals of the grating array sensing network were demodulated through optical wavelength time domain reflection demodulation technology and optical time domain segmented demodulation technology. The sidelobe suppression effect of Gaussian apodized grating was studied and simulated. The results indicat that the gratings with good spectral type and high sidelobe compression ratio can be prepared when the Gauss coefficient G = 4. A dense apodized grating array with the sidelobe compression ratio of 20.74 dB was fabricated with our grating array fabrication system. The temperature experiment results show that， for this apodized grating array sensing network， the time-domain segmentation can reach 1 m， the spatial resolution can reach 10 cm and the temperature sensitivity is 10.15 pm/℃. It is expected that the system can be applied to small-scale heat source temperature detection in cable corridors， subways and so on.