Conventional uncooled infrared temperature detectors can only detect targets in two-dimensional temperature field. We propose to achieve three-dimensional temperature field in microwave reaction chamber through binocular visual reconstruction. The infrared and visible multispectral images at two-views are acquisitioned via an infrared detector. To improve consistency of feature point detection results, we perform stereo matching at visible band with high spatial resolution. Disparity mapping with epipolar geometry constraints between two multiscale images are estimated, with which three-dimensional temperature field of depth information is reconstructed by triangulation back projection. This method does not require calibration of infrared detectors and possess certain research and application significance for carrying out the full range observation of heated objects as well as timely regulation of microwave intensity.