Micro-Raman scattaring has been used to study the characteristics of heat conduction on heavy boron-doped Si bridge in an infrared emitter. Based on the proper spectral modeling and the temperature dependence of the position of the Raman peak, the bridge temperature rise due to the heating of high power laser is obtained. Using this method and in the way of point by point, the direct imaging of heat conduction as a distribution map of temperature rise has been also obtained. Compared with the simulated temperature distribution obtained by the finite element software, the experimental and theoretical results are in agreement with each other. While experiments have revealed the local fluctuations of heat conduction in detail, reflecting the nonuniformity of the actual device, and providing experimental bases for the micro-device optimization of the structure design and its fabrication.