Abstract: Based on measured temperature by thermocouples, a finite element model of heat transfer and a nonlinear estimation model of heat flux were built for a continuous casting wide-thick slab mold for peritectic steel. The heat flux of the mold was inversely computed by using the model. In comparison with the average heat flux calculated by heat balance, the model was proved to be valid. The temperature distribution of cooper plates in the mold was analyzed under actual production conditions by the model. The averaged heat flux is 1.141 and 1.119 MW·m^-2 for the wide and the narrow face, respectively. The temperature near the mold back appears to be waved with a maximum difference about 29.6℃, whereas presents to be fiat far away from the mold back. Although the temperature decreases with the increase of the distance below the meniscus, it picks up near the mold exit. The heat flux and temperature distributions of the mold differ from those of conventional slab molds.